21706436800 has 42 divisors (see below), whose sum is σ = 53411404988. Its totient is φ = 8682574080.

The previous prime is 21706436789. The next prime is 21706436813. The reversal of 21706436800 is 863460712.

It is a self number, because there is not a number n which added to its sum of digits gives 21706436800.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6781662 + ... + 6784861.

Almost surely, 2^21706436800 is an apocalyptic number.

21706436800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21706436800 is an abundant number, since it is smaller than the sum of its proper divisors (31704968188).

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

21706436800 is a wasteful number, since it uses less digits than its factorization.

21706436800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13566545 (or 13566530 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The spelling of 21706436800 in words is "twenty-one billion, seven hundred six million, four hundred thirty-six thousand, eight hundred".