21463905 has 32 divisors (see below), whose sum is σ = 35481600. Its totient is φ = 11074752.

The previous prime is 21463847. The next prime is 21463909. The reversal of 21463905 is 50936412.

It is not a de Polignac number, because 21463905 - 2⁷ = 21463777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21463909) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 69762 + ... + 70068.

It is an arithmetic number, because the mean of its divisors is an integer number (1108800).

Almost surely, 2^21463905 is an apocalyptic number.

It is an amenable number.

21463905 is a deficient number, since it is larger than the sum of its proper divisors (14017695).

21463905 is a wasteful number, since it uses less digits than its factorization.

21463905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 21463905 is about 4632.9153888238. The cubic root of 21463905 is about 277.9091926039.

The spelling of 21463905 in words is "twenty-one million, four hundred sixty-three thousand, nine hundred five".