21520145600 has 84 divisors (see below), whose sum is σ = 54244710408. Its totient is φ = 8398080000.

The previous prime is 21520145597. The next prime is 21520145611. The reversal of 21520145600 is 654102512.

It is a self number, because there is not a number n which added to its sum of digits gives 21520145600.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98426 + ... + 229625.

It is an arithmetic number, because the mean of its divisors is an integer number (645770362).

Almost surely, 2^21520145600 is an apocalyptic number.

21520145600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21520145600 is an abundant number, since it is smaller than the sum of its proper divisors (32724564808).

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

21520145600 is a wasteful number, since it uses less digits than its factorization.

21520145600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328114 (or 328099 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The spelling of 21520145600 in words is "twenty-one billion, five hundred twenty million, one hundred forty-five thousand, six hundred".