79890642 has 48 divisors (see below), whose sum is σ = 187369728. Its totient is φ = 24455520.

The previous prime is 79890631. The next prime is 79890653. The reversal of 79890642 is 24609897.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (79890631) and next prime (79890653).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51417 + ... + 52947.

It is an arithmetic number, because the mean of its divisors is an integer number (3903536).

Almost surely, 2^79890642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79890642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93684864).

79890642 is an abundant number, since it is smaller than the sum of its proper divisors (107479086).

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

79890642 is a wasteful number, since it uses less digits than its factorization.

79890642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1775 (or 1772 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 79890642 is about 8938.1565213415. The cubic root of 79890642 is about 430.6905112517.

The spelling of 79890642 in words is "seventy-nine million, eight hundred ninety thousand, six hundred forty-two".