79356781 has 4 divisors (see below), whose sum is σ = 90693472. Its totient is φ = 68020092.

The previous prime is 79356769. The next prime is 79356793. The reversal of 79356781 is 18765397.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18765397 = 7 ⋅2680771.

It is an interprime number because it is at equal distance from previous prime (79356769) and next prime (79356793).

It is not a de Polignac number, because 79356781 - 2⁷ = 79356653 is a prime.

It is a super-3 number, since 3×79356781³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79356701) 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, 5668335 + ... + 5668348.

It is an arithmetic number, because the mean of its divisors is an integer number (22673368).

Almost surely, 2^79356781 is an apocalyptic number.

It is an amenable number.

79356781 is a deficient number, since it is larger than the sum of its proper divisors (11336691).

79356781 is a wasteful number, since it uses less digits than its factorization.

79356781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11336690.

The product of its digits is 317520, while the sum is 46.

The square root of 79356781 is about 8908.2423069874. The cubic root of 79356781 is about 429.7290180162.

The spelling of 79356781 in words is "seventy-nine million, three hundred fifty-six thousand, seven hundred eighty-one".