21879045 has 32 divisors (see below), whose sum is σ = 39811200. Its totient is φ = 11394432.

The previous prime is 21879043. The next prime is 21879047. The reversal of 21879045 is 54097812.

It is an interprime number because it is at equal distance from previous prime (21879043) and next prime (21879047).

It is not a de Polignac number, because 21879045 - 2¹ = 21879043 is a prime.

It is a super-2 number, since 2×21879045² = 957385220224050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21879041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3921 + ... + 7689.

It is an arithmetic number, because the mean of its divisors is an integer number (1244100).

Almost surely, 2^21879045 is an apocalyptic number.

It is an amenable number.

21879045 is a deficient number, since it is larger than the sum of its proper divisors (17932155).

21879045 is a wasteful number, since it uses less digits than its factorization.

21879045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3826 (or 3820 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21879045 is about 4677.5041421681. The cubic root of 21879045 is about 279.6894729218.

The spelling of 21879045 in words is "twenty-one million, eight hundred seventy-nine thousand, forty-five".