79721951 has 2 divisors, whose sum is σ = 79721952. Its totient is φ = 79721950.

The previous prime is 79721947. The next prime is 79721963. The reversal of 79721951 is 15912797.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 79721951 - 2² = 79721947 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 79721899 and 79721908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79721651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39860975 + 39860976.

It is an arithmetic number, because the mean of its divisors is an integer number (39860976).

Almost surely, 2^79721951 is an apocalyptic number.

79721951 is a deficient number, since it is larger than the sum of its proper divisors (1).

79721951 is an equidigital number, since it uses as much as digits as its factorization.

79721951 is an odious number, because the sum of its binary digits is odd.

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

The square root of 79721951 is about 8928.7149691319. The cubic root of 79721951 is about 430.3871598707.

The spelling of 79721951 in words is "seventy-nine million, seven hundred twenty-one thousand, nine hundred fifty-one".