79915421 has 4 divisors (see below), whose sum is σ = 80648700. Its totient is φ = 79182144.

The previous prime is 79915417. The next prime is 79915439. The reversal of 79915421 is 12451997.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47265625 + 32649796 = 6875^2 + 5714^2 .

It is a cyclic number.

It is not a de Polignac number, because 79915421 - 2² = 79915417 is a prime.

It is a super-3 number, since 3×79915421³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79915021) 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, 366476 + ... + 366693.

It is an arithmetic number, because the mean of its divisors is an integer number (20162175).

Almost surely, 2^79915421 is an apocalyptic number.

It is an amenable number.

79915421 is a deficient number, since it is larger than the sum of its proper divisors (733279).

79915421 is a wasteful number, since it uses less digits than its factorization.

79915421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 733278.

The product of its digits is 22680, while the sum is 38.

The square root of 79915421 is about 8939.5425498176. The cubic root of 79915421 is about 430.7350345181.

The spelling of 79915421 in words is "seventy-nine million, nine hundred fifteen thousand, four hundred twenty-one".