21939502 has 16 divisors (see below), whose sum is σ = 35526960. Its totient is φ = 10101312.

The previous prime is 21939481. The next prime is 21939517. The reversal of 21939502 is 20593912.

It is a congruent number.

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, 14053 + ... + 15535.

It is an arithmetic number, because the mean of its divisors is an integer number (2220435).

Almost surely, 2^21939502 is an apocalyptic number.

21939502 is a deficient number, since it is larger than the sum of its proper divisors (13587458).

21939502 is a wasteful number, since it uses less digits than its factorization.

21939502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2067.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 21939502 is about 4683.9622116324. The cubic root of 21939502 is about 279.9468521573.

The spelling of 21939502 in words is "twenty-one million, nine hundred thirty-nine thousand, five hundred two".