21707748031 has 2 divisors, whose sum is σ = 21707748032. Its totient is φ = 21707748030.

The previous prime is 21707747993. The next prime is 21707748053. The reversal of 21707748031 is 13084770712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21707748031 is a prime.

It is a super-2 number, since 2×21707748031² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21707748091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10853874015 + 10853874016.

It is an arithmetic number, because the mean of its divisors is an integer number (10853874016).

Almost surely, 2^21707748031 is an apocalyptic number.

21707748031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21707748031 is an equidigital number, since it uses as much as digits as its factorization.

21707748031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65856, while the sum is 40.

The spelling of 21707748031 in words is "twenty-one billion, seven hundred seven million, seven hundred forty-eight thousand, thirty-one".