21479875 has 16 divisors (see below), whose sum is σ = 26960544. Its totient is φ = 17085600.

The previous prime is 21479873. The next prime is 21479881. The reversal of 21479875 is 57897412.

It is not a de Polignac number, because 21479875 - 2¹ = 21479873 is a prime.

It is a super-2 number, since 2×21479875² = 922770060031250, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21479873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27997 + ... + 28753.

It is an arithmetic number, because the mean of its divisors is an integer number (1685034).

Almost surely, 2^21479875 is an apocalyptic number.

21479875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21479875 is a deficient number, since it is larger than the sum of its proper divisors (5480669).

21479875 is an equidigital number, since it uses as much as digits as its factorization.

21479875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999 (or 989 counting only the distinct ones).

The product of its digits is 141120, while the sum is 43.

The square root of 21479875 is about 4634.6386051126. The cubic root of 21479875 is about 277.9781006851.

It can be divided in two parts, 214 and 79875, that added together give a square (80089 = 283²).

The spelling of 21479875 in words is "twenty-one million, four hundred seventy-nine thousand, eight hundred seventy-five".