21616670 has 16 divisors (see below), whose sum is σ = 39218688. Its totient is φ = 8578080.

The previous prime is 21616669. The next prime is 21616697. The reversal of 21616670 is 7661612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7241 + ... + 9780.

It is an arithmetic number, because the mean of its divisors is an integer number (2451168).

Almost surely, 2^21616670 is an apocalyptic number.

21616670 is a deficient number, since it is larger than the sum of its proper divisors (17602018).

21616670 is a wasteful number, since it uses less digits than its factorization.

21616670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17155.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 21616670 is about 4649.3730760179. The cubic root of 21616670 is about 278.5669553773.

The spelling of 21616670 in words is "twenty-one million, six hundred sixteen thousand, six hundred seventy".