21113202031 has 4 divisors (see below), whose sum is σ = 21116025000. Its totient is φ = 21110379064.

The previous prime is 21113202017. The next prime is 21113202067. The reversal of 21113202031 is 13020231112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21113202031 - 2⁵ = 21113201999 is a prime.

It is a super-2 number, since 2×21113202031² (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 = 21113201996 and 21113202014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113202001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1400236 + ... + 1415233.

It is an arithmetic number, because the mean of its divisors is an integer number (5279006250).

Almost surely, 2^21113202031 is an apocalyptic number.

21113202031 is a deficient number, since it is larger than the sum of its proper divisors (2822969).

21113202031 is an equidigital number, since it uses as much as digits as its factorization.

21113202031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2822968.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21113202031 its reverse (13020231112), we get a palindrome (34133433143).

The spelling of 21113202031 in words is "twenty-one billion, one hundred thirteen million, two hundred two thousand, thirty-one".