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31211213111 = 136143390829
BaseRepresentation
bin11101000100010101…
…010101000100110111
32222120011101220101222
4131010111111010313
51002410032304421
622201020340555
72153304635261
oct350425250467
988504356358
1031211213111
1112266a09401
1260706a475b
132c352b4350
141721256b31
15c2a12bcab
hex744555137

31211213111 has 8 divisors (see below), whose sum is σ = 33617633280. Its totient is φ = 28805586912.

The previous prime is 31211213027. The next prime is 31211213123. The reversal of 31211213111 is 11131211213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-31211213111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31211213111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31211213171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115556 + ... + 275273.

It is an arithmetic number, because the mean of its divisors is an integer number (4202204160).

Almost surely, 231211213111 is an apocalyptic number.

31211213111 is a deficient number, since it is larger than the sum of its proper divisors (2406420169).

31211213111 is a wasteful number, since it uses less digits than its factorization.

31211213111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396985.

The product of its digits is 36, while the sum is 17.

Adding to 31211213111 its reverse (11131211213), we get a palindrome (42342424324).

It can be divided in two parts, 31211213 and 111, that multiplied together give a palindrome (3464444643).

The spelling of 31211213111 in words is "thirty-one billion, two hundred eleven million, two hundred thirteen thousand, one hundred eleven".

Divisors: 1 13 6143 79859 390829 5080777 2400862547 31211213111