21517432000 has 56 divisors (see below), whose sum is σ = 53287940160. Its totient is φ = 8606969600.

The previous prime is 21517431973. The next prime is 21517432009. The reversal of 21517432000 is 23471512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21517432009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1336840 + ... + 1352839.

It is an arithmetic number, because the mean of its divisors is an integer number (951570360).

Almost surely, 2^21517432000 is an apocalyptic number.

21517432000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21517432000 is an abundant number, since it is smaller than the sum of its proper divisors (31770508160).

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

21517432000 is an equidigital number, since it uses as much as digits as its factorization.

21517432000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2689706 (or 2689686 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The spelling of 21517432000 in words is "twenty-one billion, five hundred seventeen million, four hundred thirty-two thousand".