20939790 has 16 divisors (see below), whose sum is σ = 50255568. Its totient is φ = 5583936.

The previous prime is 20939783. The next prime is 20939803. The reversal of 20939790 is 9793902.

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, 348967 + ... + 349026.

It is an arithmetic number, because the mean of its divisors is an integer number (3140973).

Almost surely, 2^20939790 is an apocalyptic number.

20939790 is an abundant number, since it is smaller than the sum of its proper divisors (29315778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20939790 is a wasteful number, since it uses less digits than its factorization.

20939790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698003.

The product of its (nonzero) digits is 30618, while the sum is 39.

The square root of 20939790 is about 4576.0015297200. The cubic root of 20939790 is about 275.6284909138.

The spelling of 20939790 in words is "twenty million, nine hundred thirty-nine thousand, seven hundred ninety".