79857673281 has 45 divisors (see below), whose sum is σ = 126792257779. Its totient is φ = 50079646656.

The previous prime is 79857673271. The next prime is 79857673321. The reversal of 79857673281 is 18237675897.

The square root of 79857673281 is 282591.

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

It can be written as a sum of positive squares in only one way, i.e., 62172929025 + 17684744256 = 249345^2 + 132984^2 .

It is not a de Polignac number, because 79857673281 - 2⁷ = 79857673153 is a prime.

It is a super-2 number, since 2×79857673281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (79857673211) 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 44 ways as a sum of consecutive naturals, for example, 43235500 + ... + 43237346.

Almost surely, 2^79857673281 is an apocalyptic number.

79857673281 is the 282591-st square number.

79857673281 is the 141296-th centered octagonal number.

It is an amenable number.

79857673281 is a deficient number, since it is larger than the sum of its proper divisors (46934584498).

79857673281 is an frugal number, since it uses more digits than its factorization.

79857673281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3740 (or 1867 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 79857673281 in words is "seventy-nine billion, eight hundred fifty-seven million, six hundred seventy-three thousand, two hundred eighty-one".