79778515 has 8 divisors (see below), whose sum is σ = 97540848. Its totient is φ = 62618400.

The previous prime is 79778509. The next prime is 79778519. The reversal of 79778515 is 51587797.

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

It is not a de Polignac number, because 79778515 - 2⁵ = 79778483 is a prime.

It is a super-2 number, since 2×79778515² = 12729222911210450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79778519) 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, 150261 + ... + 150790.

It is an arithmetic number, because the mean of its divisors is an integer number (12192606).

Almost surely, 2^79778515 is an apocalyptic number.

79778515 is a deficient number, since it is larger than the sum of its proper divisors (17762333).

79778515 is a wasteful number, since it uses less digits than its factorization.

79778515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301109.

The product of its digits is 617400, while the sum is 49.

The square root of 79778515 is about 8931.8819405543. The cubic root of 79778515 is about 430.4889246657.

The spelling of 79778515 in words is "seventy-nine million, seven hundred seventy-eight thousand, five hundred fifteen".