21607642 has 16 divisors (see below), whose sum is σ = 37167552. Its totient is φ = 9228960.

The previous prime is 21607633. The next prime is 21607657. The reversal of 21607642 is 24670612.

It is a self number, because there is not a number n which added to its sum of digits gives 21607642.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1917 + ... + 6847.

It is an arithmetic number, because the mean of its divisors is an integer number (2322972).

Almost surely, 2^21607642 is an apocalyptic number.

21607642 is a deficient number, since it is larger than the sum of its proper divisors (15559910).

21607642 is a wasteful number, since it uses less digits than its factorization.

21607642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21607642 is about 4648.4020910416. The cubic root of 21607642 is about 278.5281696830.

The spelling of 21607642 in words is "twenty-one million, six hundred seven thousand, six hundred forty-two".