21808057000 has 64 divisors (see below), whose sum is σ = 51053970240. Its totient is φ = 8719272000.

The previous prime is 21808056937. The next prime is 21808057001. The reversal of 21808057000 is 75080812.

It is not an unprimeable number, because it can be changed into a prime (21808057001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3327727 + ... + 3334273.

It is an arithmetic number, because the mean of its divisors is an integer number (797718285).

Almost surely, 2^21808057000 is an apocalyptic number.

21808057000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21808057000 is an abundant number, since it is smaller than the sum of its proper divisors (29245913240).

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

21808057000 is a wasteful number, since it uses less digits than its factorization.

21808057000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9899 (or 9885 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 31.

The spelling of 21808057000 in words is "twenty-one billion, eight hundred eight million, fifty-seven thousand".