80415721 has 2 divisors, whose sum is σ = 80415722. Its totient is φ = 80415720.

The previous prime is 80415707. The next prime is 80415749. The reversal of 80415721 is 12751408.

It is an a-pointer prime, because the next prime (80415749) can be obtained adding 80415721 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61152400 + 19263321 = 7820^2 + 4389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80415721 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 80415721.

It is not a weakly prime, because it can be changed into another prime (80415221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40207860 + 40207861.

It is an arithmetic number, because the mean of its divisors is an integer number (40207861).

Almost surely, 2^80415721 is an apocalyptic number.

It is an amenable number.

80415721 is a deficient number, since it is larger than the sum of its proper divisors (1).

80415721 is an equidigital number, since it uses as much as digits as its factorization.

80415721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 80415721 is about 8967.4813074798. The cubic root of 80415721 is about 431.6320186724.

The spelling of 80415721 in words is "eighty million, four hundred fifteen thousand, seven hundred twenty-one".