21675357 has 64 divisors (see below), whose sum is σ = 38257920. Its totient is φ = 12130560.

The previous prime is 21675337. The next prime is 21675359. The reversal of 21675357 is 75357612.

It is not a de Polignac number, because 21675357 - 2¹⁰ = 21674333 is a prime.

It is a super-2 number, since 2×21675357² = 939642202154898, which contains 22 as substring.

Its product of digits (44100) is a multiple of the sum of its prime divisors (84).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675359) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 408943 + ... + 408995.

It is an arithmetic number, because the mean of its divisors is an integer number (597780).

Almost surely, 2^21675357 is an apocalyptic number.

21675357 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21675357 is a deficient number, since it is larger than the sum of its proper divisors (16582563).

21675357 is an equidigital number, since it uses as much as digits as its factorization.

21675357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 84 counting only the distinct ones).

The product of its digits is 44100, while the sum is 36.

The square root of 21675357 is about 4655.6800792151. The cubic root of 21675357 is about 278.8188209758.

The spelling of 21675357 in words is "twenty-one million, six hundred seventy-five thousand, three hundred fifty-seven".