21426408 has 24 divisors (see below), whose sum is σ = 58030050. Its totient is φ = 7142112.

The previous prime is 21426401. The next prime is 21426413. The reversal of 21426408 is 80462412.

21426408 is a `hidden beast` number, since 2 + 14 + 2 + 640 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21178404 + 248004 = 4602^2 + 498^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (21426401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 148723 + ... + 148866.

Almost surely, 2^21426408 is an apocalyptic number.

It is an amenable number.

21426408 is an abundant number, since it is smaller than the sum of its proper divisors (36603642).

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

21426408 is a wasteful number, since it uses less digits than its factorization.

21426408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297601 (or 297594 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21426408 is about 4628.8668159713. The cubic root of 21426408 is about 277.7472643935.

The spelling of 21426408 in words is "twenty-one million, four hundred twenty-six thousand, four hundred eight".