21630610 has 16 divisors (see below), whose sum is σ = 39004416. Its totient is φ = 8636848.

The previous prime is 21630601. The next prime is 21630611. The reversal of 21630610 is 1603612.

It is not an unprimeable number, because it can be changed into a prime (21630611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5247 + ... + 8413.

It is an arithmetic number, because the mean of its divisors is an integer number (2437776).

Almost surely, 2^21630610 is an apocalyptic number.

21630610 is a deficient number, since it is larger than the sum of its proper divisors (17373806).

21630610 is a wasteful number, since it uses less digits than its factorization.

21630610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3857.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21630610 is about 4650.8719612563. The cubic root of 21630610 is about 278.6268225836.

The spelling of 21630610 in words is "twenty-one million, six hundred thirty thousand, six hundred ten".