21867975 has 30 divisors (see below), whose sum is σ = 40510800. Its totient is φ = 11661840.

The previous prime is 21867973. The next prime is 21867977. The reversal of 21867975 is 57976812.

It is an interprime number because it is at equal distance from previous prime (21867973) and next prime (21867977).

It is not a de Polignac number, because 21867975 - 2¹ = 21867973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21867975.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21867973) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 3375 + ... + 7424.

It is an arithmetic number, because the mean of its divisors is an integer number (1350360).

Almost surely, 2^21867975 is an apocalyptic number.

21867975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21867975 is a deficient number, since it is larger than the sum of its proper divisors (18642825).

21867975 is a wasteful number, since it uses less digits than its factorization.

21867975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10821 (or 10807 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 21867975 is about 4676.3206690731. The cubic root of 21867975 is about 279.6422940680.

The spelling of 21867975 in words is "twenty-one million, eight hundred sixty-seven thousand, nine hundred seventy-five".