79815973 has 4 divisors (see below), whose sum is σ = 80072928. Its totient is φ = 79559020.

The previous prime is 79815943. The next prime is 79815977. The reversal of 79815973 is 37951897.

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: 37951897 = 73 ⋅519889.

It is a cyclic number.

It is not a de Polignac number, because 79815973 - 2¹³ = 79807781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79815977) 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, 128011 + ... + 128632.

It is an arithmetic number, because the mean of its divisors is an integer number (20018232).

Almost surely, 2^79815973 is an apocalyptic number.

It is an amenable number.

79815973 is a deficient number, since it is larger than the sum of its proper divisors (256955).

79815973 is a wasteful number, since it uses less digits than its factorization.

79815973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256954.

The product of its digits is 476280, while the sum is 49.

The square root of 79815973 is about 8933.9785650067. The cubic root of 79815973 is about 430.5562892148.

The spelling of 79815973 in words is "seventy-nine million, eight hundred fifteen thousand, nine hundred seventy-three".