79901221 has 4 divisors (see below), whose sum is σ = 80319744. Its totient is φ = 79482700.

The previous prime is 79901219. The next prime is 79901233. The reversal of 79901221 is 12210997.

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: 12210997 = 149 ⋅81953.

It is a cyclic number.

It is not a de Polignac number, because 79901221 - 2¹ = 79901219 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79901621) 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, 208975 + ... + 209356.

It is an arithmetic number, because the mean of its divisors is an integer number (20079936).

Almost surely, 2^79901221 is an apocalyptic number.

It is an amenable number.

79901221 is a deficient number, since it is larger than the sum of its proper divisors (418523).

79901221 is a wasteful number, since it uses less digits than its factorization.

79901221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418522.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 79901221 is about 8938.7482904487. The cubic root of 79901221 is about 430.7095208783.

The spelling of 79901221 in words is "seventy-nine million, nine hundred one thousand, two hundred twenty-one".