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31220130013 = 93481333973
BaseRepresentation
bin11101000100110111…
…010110000011011101
32222120210011221002121
4131010313112003131
51002414323130023
622201535422541
72153443504132
oct350467260335
988523157077
1031220130013
1112270a49846
126073684a51
132c370b6c17
1417224d8589
15c2acddd5d
hex744dd60dd

31220130013 has 4 divisors (see below), whose sum is σ = 31220557468. Its totient is φ = 31219702560.

The previous prime is 31220129981. The next prime is 31220130023. The reversal of 31220130013 is 31003102213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31003102213 = 144721425779.

It can be written as a sum of positive squares in 2 ways, for example, as 11915250649 + 19304879364 = 109157^2 + 138942^2 .

It is a cyclic number.

It is not a de Polignac number, because 31220130013 - 25 = 31220129981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220130023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73506 + ... + 260467.

It is an arithmetic number, because the mean of its divisors is an integer number (7805139367).

Almost surely, 231220130013 is an apocalyptic number.

It is an amenable number.

31220130013 is a deficient number, since it is larger than the sum of its proper divisors (427455).

31220130013 is an equidigital number, since it uses as much as digits as its factorization.

31220130013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427454.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 31220130013 its reverse (31003102213), we get a palindrome (62223232226).

The spelling of 31220130013 in words is "thirty-one billion, two hundred twenty million, one hundred thirty thousand, thirteen".

Divisors: 1 93481 333973 31220130013