79609640 has 128 divisors (see below), whose sum is σ = 214617600. Its totient is φ = 26234880.

The previous prime is 79609633. The next prime is 79609679. The reversal of 79609640 is 4690697.

79609640 = 2156² + 2157² + ... + 2172².

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 216737 + ... + 217103.

It is an arithmetic number, because the mean of its divisors is an integer number (1676700).

Almost surely, 2^79609640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79609640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107308800).

79609640 is an abundant number, since it is smaller than the sum of its proper divisors (135007960).

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

79609640 is a wasteful number, since it uses less digits than its factorization.

79609640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 79609640 is about 8922.4234376093. The cubic root of 79609640 is about 430.1849573891.

The spelling of 79609640 in words is "seventy-nine million, six hundred nine thousand, six hundred forty".