21708701031 has 4 divisors (see below), whose sum is σ = 28944934712. Its totient is φ = 14472467352.

The previous prime is 21708700999. The next prime is 21708701039. The reversal of 21708701031 is 13010780712.

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

It is not a de Polignac number, because 21708701031 - 2⁵ = 21708700999 is a prime.

It is a super-2 number, since 2×21708701031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21708701031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21708701039) 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, 3618116836 + ... + 3618116841.

It is an arithmetic number, because the mean of its divisors is an integer number (7236233678).

Almost surely, 2^21708701031 is an apocalyptic number.

21708701031 is a deficient number, since it is larger than the sum of its proper divisors (7236233681).

21708701031 is an equidigital number, since it uses as much as digits as its factorization.

21708701031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7236233680.

The product of its (nonzero) digits is 2352, while the sum is 30.

The spelling of 21708701031 in words is "twenty-one billion, seven hundred eight million, seven hundred one thousand, thirty-one".