79381521 has 6 divisors (see below), whose sum is σ = 114662210. Its totient is φ = 52921008.

The previous prime is 79381513. The next prime is 79381529. The reversal of 79381521 is 12518397.

It is an interprime number because it is at equal distance from previous prime (79381513) and next prime (79381529).

It can be written as a sum of positive squares in only one way, i.e., 65610000 + 13771521 = 8100^2 + 3711^2 .

It is not a de Polignac number, because 79381521 - 2³ = 79381513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79381529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4410076 + ... + 4410093.

Almost surely, 2^79381521 is an apocalyptic number.

It is an amenable number.

79381521 is a deficient number, since it is larger than the sum of its proper divisors (35280689).

79381521 is a wasteful number, since it uses less digits than its factorization.

79381521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8820175 (or 8820172 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 79381521 is about 8909.6308004316. The cubic root of 79381521 is about 429.7736703284.

The spelling of 79381521 in words is "seventy-nine million, three hundred eighty-one thousand, five hundred twenty-one".