79661761 has 4 divisors (see below), whose sum is σ = 80753092. Its totient is φ = 78570432.

The previous prime is 79661759. The next prime is 79661767. The reversal of 79661761 is 16716697.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17172736 + 62489025 = 4144^2 + 7905^2 .

It is a cyclic number.

It is not a de Polignac number, because 79661761 - 2¹ = 79661759 is a prime.

It is a super-2 number, since 2×79661761² = 12691992331242242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79661767) 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, 545556 + ... + 545701.

It is an arithmetic number, because the mean of its divisors is an integer number (20188273).

Almost surely, 2^79661761 is an apocalyptic number.

It is an amenable number.

79661761 is a deficient number, since it is larger than the sum of its proper divisors (1091331).

79661761 is a wasteful number, since it uses less digits than its factorization.

79661761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091330.

The product of its digits is 95256, while the sum is 43.

The square root of 79661761 is about 8925.3437468817. The cubic root of 79661761 is about 430.2788186298.

The spelling of 79661761 in words is "seventy-nine million, six hundred sixty-one thousand, seven hundred sixty-one".