21705649592 has 16 divisors (see below), whose sum is σ = 44397919800. Its totient is φ = 9866204320.

The previous prime is 21705649591. The next prime is 21705649613. The reversal of 21705649592 is 29594650712.

It is a super-2 number, since 2×21705649592² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21705649592.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21705649591) 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, 123327467 + ... + 123327642.

Almost surely, 2^21705649592 is an apocalyptic number.

21705649592 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21705649592 is an abundant number, since it is smaller than the sum of its proper divisors (22692270208).

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

21705649592 is a wasteful number, since it uses less digits than its factorization.

21705649592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246655126 (or 246655122 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 50.

The spelling of 21705649592 in words is "twenty-one billion, seven hundred five million, six hundred forty-nine thousand, five hundred ninety-two".