21572995 has 16 divisors (see below), whose sum is σ = 26673408. Its totient is φ = 16742880.

The previous prime is 21572989. The next prime is 21573023. The reversal of 21572995 is 59927512.

It is not a de Polignac number, because 21572995 - 2⁷ = 21572867 is a prime.

It is a super-2 number, since 2×21572995² = 930788226540050, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (56700) is a multiple of the sum of its prime divisors (1050).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 23332 + ... + 24238.

It is an arithmetic number, because the mean of its divisors is an integer number (1667088).

Almost surely, 2^21572995 is an apocalyptic number.

21572995 is a deficient number, since it is larger than the sum of its proper divisors (5100413).

21572995 is an equidigital number, since it uses as much as digits as its factorization.

21572995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050.

The product of its digits is 56700, while the sum is 40.

The square root of 21572995 is about 4644.6738313901. The cubic root of 21572995 is about 278.3792204057.

It can be divided in two parts, 2157 and 2995, that multiplied together give a triangular number (6460215 = T₃₅₉₄).

The spelling of 21572995 in words is "twenty-one million, five hundred seventy-two thousand, nine hundred ninety-five".