79685907840 has 640 divisors, whose sum is σ = 354809790720. Its totient is φ = 16557281280.

The previous prime is 79685907839. The next prime is 79685907853. The reversal of 79685907840 is 4870958697.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3981699 + ... + 4001661.

It is an arithmetic number, because the mean of its divisors is an integer number (554390298).

Almost surely, 2^79685907840 is an apocalyptic number.

79685907840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 79685907840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177404895360).

79685907840 is an abundant number, since it is smaller than the sum of its proper divisors (275123882880).

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

79685907840 is a wasteful number, since it uses less digits than its factorization.

79685907840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20012 (or 19991 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 63.

The spelling of 79685907840 in words is "seventy-nine billion, six hundred eighty-five million, nine hundred seven thousand, eight hundred forty".