79331561 has 4 divisors (see below), whose sum is σ = 80117124. Its totient is φ = 78546000.

The previous prime is 79331557. The next prime is 79331579. The reversal of 79331561 is 16513397.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16513397 = 1151 ⋅14347.

It can be written as a sum of positive squares in 2 ways, for example, as 72777961 + 6553600 = 8531^2 + 2560^2 .

It is a cyclic number.

It is not a de Polignac number, because 79331561 - 2² = 79331557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79331261) 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, 392630 + ... + 392831.

It is an arithmetic number, because the mean of its divisors is an integer number (20029281).

Almost surely, 2^79331561 is an apocalyptic number.

It is an amenable number.

79331561 is a deficient number, since it is larger than the sum of its proper divisors (785563).

79331561 is a wasteful number, since it uses less digits than its factorization.

79331561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 785562.

The product of its digits is 17010, while the sum is 35.

The square root of 79331561 is about 8906.8266515073. The cubic root of 79331561 is about 429.6834898165.

The spelling of 79331561 in words is "seventy-nine million, three hundred thirty-one thousand, five hundred sixty-one".