21630364 has 18 divisors (see below), whose sum is σ = 44033640. Its totient is φ = 9270072.

The previous prime is 21630359. The next prime is 21630383. The reversal of 21630364 is 46303612.

It is a congruent 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 5 ways as a sum of consecutive naturals, for example, 54984 + ... + 55375.

Almost surely, 2^21630364 is an apocalyptic number.

It is an amenable number.

21630364 is an abundant number, since it is smaller than the sum of its proper divisors (22403276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21630364 is a wasteful number, since it uses less digits than its factorization.

21630364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110377 (or 110368 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 21630364 is about 4650.8455145274. The cubic root of 21630364 is about 278.6257663265.

Adding to 21630364 its reverse (46303612), we get a palindrome (67933976).

The spelling of 21630364 in words is "twenty-one million, six hundred thirty thousand, three hundred sixty-four".