21873546 has 12 divisors (see below), whose sum is σ = 47392722. Its totient is φ = 7291176.

The previous prime is 21873539. The next prime is 21873589. The reversal of 21873546 is 64537812.

It can be written as a sum of positive squares in only one way, i.e., 12638025 + 9235521 = 3555^2 + 3039^2 .

It is a super-2 number, since 2×21873546² = 956904029228232, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21873546.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 607581 + ... + 607616.

Almost surely, 2^21873546 is an apocalyptic number.

21873546 is an abundant number, since it is smaller than the sum of its proper divisors (25519176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21873546 is a wasteful number, since it uses less digits than its factorization.

21873546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1215205 (or 1215202 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21873546 is about 4676.9162917461. The cubic root of 21873546 is about 279.6660389117. Note that the first 3 decimals are identical.

The spelling of 21873546 in words is "twenty-one million, eight hundred seventy-three thousand, five hundred forty-six".