21688461460 has 48 divisors (see below), whose sum is σ = 46264184064. Its totient is φ = 8538761088.

The previous prime is 21688461413. The next prime is 21688461481. The reversal of 21688461460 is 6416488612.

It is a self number, because there is not a number n which added to its sum of digits gives 21688461460.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1772082 + ... + 1784278.

It is an arithmetic number, because the mean of its divisors is an integer number (963837168).

Almost surely, 2^21688461460 is an apocalyptic number.

21688461460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21688461460 is an abundant number, since it is smaller than the sum of its proper divisors (24575722604).

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

21688461460 is a wasteful number, since it uses less digits than its factorization.

21688461460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13600 (or 13598 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 46.

The spelling of 21688461460 in words is "twenty-one billion, six hundred eighty-eight million, four hundred sixty-one thousand, four hundred sixty".