21630465 has 24 divisors (see below), whose sum is σ = 39124800. Its totient is φ = 11034144.

The previous prime is 21630461. The next prime is 21630487. The reversal of 21630465 is 56403612.

21630465 is a `hidden beast` number, since 21 + 630 + 4 + 6 + 5 = 666.

It is not a de Polignac number, because 21630465 - 2² = 21630461 is a prime.

It is a super-2 number, since 2×21630465² = 935754032232450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21630461) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9415 + ... + 11484.

It is an arithmetic number, because the mean of its divisors is an integer number (1630200).

Almost surely, 2^21630465 is an apocalyptic number.

It is an amenable number.

21630465 is a deficient number, since it is larger than the sum of its proper divisors (17494335).

21630465 is a wasteful number, since it uses less digits than its factorization.

21630465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20933 (or 20930 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 21630465 is about 4650.8563727555. The cubic root of 21630465 is about 278.6261999940.

The spelling of 21630465 in words is "twenty-one million, six hundred thirty thousand, four hundred sixty-five".