21732575 has 6 divisors (see below), whose sum is σ = 26948424. Its totient is φ = 17386040.

The previous prime is 21732551. The next prime is 21732577. The reversal of 21732575 is 57523712.

It is not a de Polignac number, because 21732575 - 2²⁴ = 4955359 is a prime.

It is a super-2 number, since 2×21732575² = 944609632261250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21732577) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 434627 + ... + 434676.

It is an arithmetic number, because the mean of its divisors is an integer number (4491404).

Almost surely, 2^21732575 is an apocalyptic number.

21732575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21732575 is a deficient number, since it is larger than the sum of its proper divisors (5215849).

21732575 is an equidigital number, since it uses as much as digits as its factorization.

21732575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869313 (or 869308 counting only the distinct ones).

The product of its digits is 14700, while the sum is 32.

The square root of 21732575 is about 4661.8209961345. The cubic root of 21732575 is about 279.0639447819.

The spelling of 21732575 in words is "twenty-one million, seven hundred thirty-two thousand, five hundred seventy-five".