21455404 has 12 divisors (see below), whose sum is σ = 37800000. Its totient is φ = 10655408.

The previous prime is 21455393. The next prime is 21455429. The reversal of 21455404 is 40455412.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17404 + ... + 18595.

It is an arithmetic number, because the mean of its divisors is an integer number (3150000).

Almost surely, 2^21455404 is an apocalyptic number.

It is an amenable number.

21455404 is a deficient number, since it is larger than the sum of its proper divisors (16344596).

21455404 is a wasteful number, since it uses less digits than its factorization.

21455404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36152 (or 36150 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 25.

The square root of 21455404 is about 4631.9978411049. The cubic root of 21455404 is about 277.8724981625.

The spelling of 21455404 in words is "twenty-one million, four hundred fifty-five thousand, four hundred four".