21730875 has 32 divisors (see below), whose sum is σ = 36481536. Its totient is φ = 11487200.

The previous prime is 21730871. The next prime is 21730903. The reversal of 21730875 is 57803712.

It is not a de Polignac number, because 21730875 - 2² = 21730871 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21730871) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62452 + ... + 62798.

It is an arithmetic number, because the mean of its divisors is an integer number (1140048).

Almost surely, 2^21730875 is an apocalyptic number.

21730875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21730875 is a deficient number, since it is larger than the sum of its proper divisors (14750661).

21730875 is a wasteful number, since it uses less digits than its factorization.

21730875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532 (or 522 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 21730875 is about 4661.6386603854. The cubic root of 21730875 is about 279.0566681311.

The spelling of 21730875 in words is "twenty-one million, seven hundred thirty thousand, eight hundred seventy-five".