79661569 has 8 divisors (see below), whose sum is σ = 87615360. Its totient is φ = 71968656.

The previous prime is 79661501. The next prime is 79661587. The reversal of 79661569 is 96516697.

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

It is a de Polignac number, because none of the positive numbers 2^k-79661569 is a prime.

It is a super-2 number, since 2×79661569² = 12691931151083522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79661369) 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, 64579 + ... + 65800.

It is an arithmetic number, because the mean of its divisors is an integer number (10951920).

Almost surely, 2^79661569 is an apocalyptic number.

It is an amenable number.

79661569 is a deficient number, since it is larger than the sum of its proper divisors (7953791).

79661569 is a wasteful number, since it uses less digits than its factorization.

79661569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130439.

The product of its digits is 612360, while the sum is 49.

The square root of 79661569 is about 8925.3329909869. The cubic root of 79661569 is about 430.2784729449.

The spelling of 79661569 in words is "seventy-nine million, six hundred sixty-one thousand, five hundred sixty-nine".