21313630 has 32 divisors (see below), whose sum is σ = 43495200. Its totient is φ = 7454592.

The previous prime is 21313609. The next prime is 21313657. The reversal of 21313630 is 3631312.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a junction number, because it is equal to n+sod(n) for n = 21313598 and 21313607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1845 + ... + 6784.

It is an arithmetic number, because the mean of its divisors is an integer number (1359225).

Almost surely, 2^21313630 is an apocalyptic number.

21313630 is an abundant number, since it is smaller than the sum of its proper divisors (22181570).

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

21313630 is a wasteful number, since it uses less digits than its factorization.

21313630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8668.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 21313630 is about 4616.6687123943. The cubic root of 21313630 is about 277.2590988879.

Adding to 21313630 its reverse (3631312), we get a palindrome (24944942).

The spelling of 21313630 in words is "twenty-one million, three hundred thirteen thousand, six hundred thirty".