21105730031 has 8 divisors (see below), whose sum is σ = 21788609664. Its totient is φ = 20422978560.

The previous prime is 21105730007. The next prime is 21105730049. The reversal of 21105730031 is 13003750112.

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

It is a de Polignac number, because none of the positive numbers 2^k-21105730031 is a prime.

It is a super-2 number, since 2×21105730031² (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 = 21105729979 and 21105730006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105730001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391871 + ... + 442463.

It is an arithmetic number, because the mean of its divisors is an integer number (2723576208).

Almost surely, 2^21105730031 is an apocalyptic number.

21105730031 is a deficient number, since it is larger than the sum of its proper divisors (682879633).

21105730031 is a wasteful number, since it uses less digits than its factorization.

21105730031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64081.

The product of its (nonzero) digits is 630, while the sum is 23.

The spelling of 21105730031 in words is "twenty-one billion, one hundred five million, seven hundred thirty thousand, thirty-one".