21031201111 has 8 divisors (see below), whose sum is σ = 21135198384. Its totient is φ = 20927441280.

The previous prime is 21031201097. The next prime is 21031201123. The reversal of 21031201111 is 11110213012.

It is a happy number.

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 2^k-21031201111 is a prime.

It is a super-2 number, since 2×21031201111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031201091 and 21031201100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031201811) 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 7 ways as a sum of consecutive naturals, for example, 119551 + ... + 237391.

It is an arithmetic number, because the mean of its divisors is an integer number (2641899798).

Almost surely, 2^21031201111 is an apocalyptic number.

21031201111 is a deficient number, since it is larger than the sum of its proper divisors (103997273).

21031201111 is a wasteful number, since it uses less digits than its factorization.

21031201111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118721.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21031201111 its reverse (11110213012), we get a palindrome (32141414123).

The spelling of 21031201111 in words is "twenty-one billion, thirty-one million, two hundred one thousand, one hundred eleven".