7890639 has 8 divisors (see below), whose sum is σ = 10883760. Its totient is φ = 5078976.

The previous prime is 7890611. The next prime is 7890661. The reversal of 7890639 is 9360987.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7890639 - 2⁵ = 7890607 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7890639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7890439) 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, 45262 + ... + 45435.

It is an arithmetic number, because the mean of its divisors is an integer number (1360470).

Almost surely, 2^7890639 is an apocalyptic number.

7890639 is a deficient number, since it is larger than the sum of its proper divisors (2993121).

7890639 is a wasteful number, since it uses less digits than its factorization.

7890639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90729.

The product of its (nonzero) digits is 81648, while the sum is 42.

The square root of 7890639 is about 2809.0281237467. The cubic root of 7890639 is about 199.0844737870.

The spelling of 7890639 in words is "seven million, eight hundred ninety thousand, six hundred thirty-nine".