21765057400 has 48 divisors (see below), whose sum is σ = 50613769440. Its totient is φ = 8704300800.

The previous prime is 21765057397. The next prime is 21765057421. The reversal of 21765057400 is 475056712.

It is a self number, because there is not a number n which added to its sum of digits gives 21765057400.

It is a congruent number.

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, 1615492 + ... + 1628908.

It is an arithmetic number, because the mean of its divisors is an integer number (1054453530).

Almost surely, 2^21765057400 is an apocalyptic number.

21765057400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21765057400 is an abundant number, since it is smaller than the sum of its proper divisors (28848712040).

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

21765057400 is a wasteful number, since it uses less digits than its factorization.

21765057400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21544 (or 21535 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 37.

The spelling of 21765057400 in words is "twenty-one billion, seven hundred sixty-five million, fifty-seven thousand, four hundred".