79715921 has 4 divisors (see below), whose sum is σ = 79735872. Its totient is φ = 79695972.

The previous prime is 79715899. The next prime is 79715957. The reversal of 79715921 is 12951797.

It is a happy number.

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: 12951797 = 367 ⋅35291.

It is a cyclic number.

It is not a de Polignac number, because 79715921 - 2¹⁴ = 79699537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79715981) 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 3 ways as a sum of consecutive naturals, for example, 1685 + ... + 12738.

It is an arithmetic number, because the mean of its divisors is an integer number (19933968).

Almost surely, 2^79715921 is an apocalyptic number.

It is an amenable number.

79715921 is a deficient number, since it is larger than the sum of its proper divisors (19951).

79715921 is a wasteful number, since it uses less digits than its factorization.

79715921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19950.

The product of its digits is 39690, while the sum is 41.

The square root of 79715921 is about 8928.3772881750. The cubic root of 79715921 is about 430.3763084052.

The spelling of 79715921 in words is "seventy-nine million, seven hundred fifteen thousand, nine hundred twenty-one".