21512630 has 8 divisors (see below), whose sum is σ = 38722752. Its totient is φ = 8605048.

The previous prime is 21512609. The next prime is 21512653. The reversal of 21512630 is 3621512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1075622 + ... + 1075641.

It is an arithmetic number, because the mean of its divisors is an integer number (4840344).

Almost surely, 2^21512630 is an apocalyptic number.

21512630 is a deficient number, since it is larger than the sum of its proper divisors (17210122).

21512630 is a wasteful number, since it uses less digits than its factorization.

21512630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151270.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21512630 is about 4638.1709757188. The cubic root of 21512630 is about 278.1193266528.

The spelling of 21512630 in words is "twenty-one million, five hundred twelve thousand, six hundred thirty".