7920639 has 8 divisors (see below), whose sum is σ = 11734320. Its totient is φ = 5280408.

The previous prime is 7920629. The next prime is 7920641. The reversal of 7920639 is 9360297.

It is not a de Polignac number, because 7920639 - 2¹⁵ = 7887871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7920629) 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, 146652 + ... + 146705.

It is an arithmetic number, because the mean of its divisors is an integer number (1466790).

Almost surely, 2^7920639 is an apocalyptic number.

7920639 is a deficient number, since it is larger than the sum of its proper divisors (3813681).

7920639 is a wasteful number, since it uses less digits than its factorization.

7920639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293366 (or 293360 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 7920639 is about 2814.3629829857. The cubic root of 7920639 is about 199.3364593368.

The spelling of 7920639 in words is "seven million, nine hundred twenty thousand, six hundred thirty-nine".