21455005 has 32 divisors (see below), whose sum is σ = 31102848. Its totient is φ = 13996800.

The previous prime is 21454997. The next prime is 21455011. The reversal of 21455005 is 50055412.

It is not a de Polignac number, because 21455005 - 2³ = 21454997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26050 + ... + 26860.

It is an arithmetic number, because the mean of its divisors is an integer number (971964).

Almost surely, 2^21455005 is an apocalyptic number.

It is an amenable number.

21455005 is a deficient number, since it is larger than the sum of its proper divisors (9647843).

21455005 is a wasteful number, since it uses less digits than its factorization.

21455005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 21455005 is about 4631.9547709363. The cubic root of 21455005 is about 277.8707756467.

The spelling of 21455005 in words is "twenty-one million, four hundred fifty-five thousand, five".