21708365492 has 24 divisors (see below), whose sum is σ = 43881082560. Its totient is φ = 9287000960.

The previous prime is 21708365473. The next prime is 21708365521. The reversal of 21708365492 is 29456380712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14510192 + ... + 14511687.

It is an arithmetic number, because the mean of its divisors is an integer number (1828378440).

It is a 1-persistent number, because it is pandigital, but 2⋅21708365492 = 43416730984 is not.

Almost surely, 2^21708365492 is an apocalyptic number.

21708365492 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21708365492 is an abundant number, since it is smaller than the sum of its proper divisors (22172717068).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21708365492 is a wasteful number, since it uses less digits than its factorization.

21708365492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29021911 (or 29021909 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 47.

The spelling of 21708365492 in words is "twenty-one billion, seven hundred eight million, three hundred sixty-five thousand, four hundred ninety-two".