79391515225 has 81 divisors (see below), whose sum is σ = 111583581501. Its totient is φ = 55992340800.

The previous prime is 79391515223. The next prime is 79391515249. The reversal of 79391515225 is 52251519397.

The square root of 79391515225 is 281765.

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

It can be written as a sum of positive squares in 4 ways, for example, as 291077721 + 79100437504 = 17061^2 + 281248^2 .

It is not a de Polignac number, because 79391515225 - 2¹ = 79391515223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79391515223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 728362471 + ... + 728362579.

Almost surely, 2^79391515225 is an apocalyptic number.

79391515225 is the 281765-th square number.

79391515225 is the 140883-rd centered octagonal number.

It is an amenable number.

79391515225 is a deficient number, since it is larger than the sum of its proper divisors (32192066276).

79391515225 is a wasteful number, since it uses less digits than its factorization.

79391515225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 172 counting only the distinct ones).

The product of its digits is 850500, while the sum is 49.

Multiplying 79391515225 by its sum of digits (49), we get a square (3890184246025 = 1972355²).

The spelling of 79391515225 in words is "seventy-nine billion, three hundred ninety-one million, five hundred fifteen thousand, two hundred twenty-five".