21461408 has 12 divisors (see below), whose sum is σ = 42252210. Its totient is φ = 10730688.

The previous prime is 21461399. The next prime is 21461413. The reversal of 21461408 is 80416412.

It can be written as a sum of positive squares in only one way, i.e., 19114384 + 2347024 = 4372^2 + 1532^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335303 + ... + 335366.

Almost surely, 2^21461408 is an apocalyptic number.

It is an amenable number.

21461408 is a deficient number, since it is larger than the sum of its proper divisors (20790802).

21461408 is an equidigital number, since it uses as much as digits as its factorization.

21461408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670679 (or 670671 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21461408 is about 4632.6458962455. The cubic root of 21461408 is about 277.8984153453.

The spelling of 21461408 in words is "twenty-one million, four hundred sixty-one thousand, four hundred eight".