21125760 has 64 divisors (see below), whose sum is σ = 67344480. Its totient is φ = 5633024.

The previous prime is 21125749. The next prime is 21125761. The reversal of 21125760 is 6752112.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21125760.

It is not an unprimeable number, because it can be changed into a prime (21125761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3582 + ... + 7421.

Almost surely, 2^21125760 is an apocalyptic number.

21125760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21125760 is an abundant number, since it is smaller than the sum of its proper divisors (46218720).

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

21125760 is a wasteful number, since it uses less digits than its factorization.

21125760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11025 (or 11013 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21125760 is about 4596.2767540695. The cubic root of 21125760 is about 276.4420557281.

Adding to 21125760 its reverse (6752112), we get a palindrome (27877872).

The spelling of 21125760 in words is "twenty-one million, one hundred twenty-five thousand, seven hundred sixty".