21795560 has 16 divisors (see below), whose sum is σ = 49040100. Its totient is φ = 8718208.

The previous prime is 21795541. The next prime is 21795563. The reversal of 21795560 is 6559712.

It can be written as a sum of positive squares in 2 ways, for example, as 21696964 + 98596 = 4658^2 + 314^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21795560.

It is not an unprimeable number, because it can be changed into a prime (21795563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272405 + ... + 272484.

Almost surely, 2^21795560 is an apocalyptic number.

21795560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21795560 is an abundant number, since it is smaller than the sum of its proper divisors (27244540).

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

21795560 is a wasteful number, since it uses less digits than its factorization.

21795560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544900 (or 544896 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 35.

The square root of 21795560 is about 4668.5715159993. The cubic root of 21795560 is about 279.3332776388. Note that the first 3 decimals are identical.

The spelling of 21795560 in words is "twenty-one million, seven hundred ninety-five thousand, five hundred sixty".