79405921 has 27 divisors (see below), whose sum is σ = 98964369. Its totient is φ = 63517608.

The previous prime is 79405901. The next prime is 79405933. The reversal of 79405921 is 12950497.

79405921 = 1³ + 2³ + ... + 133³.

The square root of 79405921 is 8911.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 79405921 - 2⁹ = 79405409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (79405901) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1185130 + ... + 1185196.

It is an arithmetic number, because the mean of its divisors is an integer number (3665347).

Almost surely, 2^79405921 is an apocalyptic number.

79405921 is the 8911-st square number.

79405921 is the 4456-th centered octagonal number.

It is an amenable number.

79405921 is a deficient number, since it is larger than the sum of its proper divisors (19558448).

79405921 is an equidigital number, since it uses as much as digits as its factorization.

79405921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 37.

The cubic root of 79405921 is about 429.8176999010.

It can be divided in two parts, 7940 and 5921, that added together give a triangular number (13861 = T₁₆₆).

The spelling of 79405921 in words is "seventy-nine million, four hundred five thousand, nine hundred twenty-one".