79617640 has 16 divisors (see below), whose sum is σ = 179139780. Its totient is φ = 31847040.

The previous prime is 79617631. The next prime is 79617649. The reversal of 79617640 is 4671697.

It is an interprime number because it is at equal distance from previous prime (79617631) and next prime (79617649).

It can be written as a sum of positive squares in 2 ways, for example, as 78464164 + 1153476 = 8858^2 + 1074^2 .

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 1990441 = 79617640 / (7 + 9 + 6 + 1 + 7 + 6 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 79617593 and 79617602.

It is not an unprimeable number, because it can be changed into a prime (79617649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 995181 + ... + 995260.

Almost surely, 2^79617640 is an apocalyptic number.

It is an amenable number.

79617640 is an abundant number, since it is smaller than the sum of its proper divisors (99522140).

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

79617640 is a wasteful number, since it uses less digits than its factorization.

79617640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1990452 (or 1990448 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 79617640 is about 8922.8717350414. The cubic root of 79617640 is about 430.1993667177.

The spelling of 79617640 in words is "seventy-nine million, six hundred seventeen thousand, six hundred forty".