21524975 has 12 divisors (see below), whose sum is σ = 28261584. Its totient is φ = 16206720.

The previous prime is 21524969. The next prime is 21524977. The reversal of 21524975 is 57942512.

It is not a de Polignac number, because 21524975 - 2⁸ = 21524719 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21524977) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24899 + ... + 25748.

It is an arithmetic number, because the mean of its divisors is an integer number (2355132).

Almost surely, 2^21524975 is an apocalyptic number.

21524975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21524975 is a deficient number, since it is larger than the sum of its proper divisors (6736609).

21524975 is a wasteful number, since it uses less digits than its factorization.

21524975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50674 (or 50669 counting only the distinct ones).

The product of its digits is 25200, while the sum is 35.

The square root of 21524975 is about 4639.5015896107. The cubic root of 21524975 is about 278.1725159738.

The spelling of 21524975 in words is "twenty-one million, five hundred twenty-four thousand, nine hundred seventy-five".