79071721 has 2 divisors, whose sum is σ = 79071722. Its totient is φ = 79071720.

The previous prime is 79071703. The next prime is 79071779. The reversal of 79071721 is 12717097.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45373696 + 33698025 = 6736^2 + 5805^2 .

It is a cyclic number.

It is not a de Polignac number, because 79071721 - 2¹⁹ = 78547433 is a prime.

It is not a weakly prime, because it can be changed into another prime (79071791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39535860 + 39535861.

It is an arithmetic number, because the mean of its divisors is an integer number (39535861).

Almost surely, 2^79071721 is an apocalyptic number.

It is an amenable number.

79071721 is a deficient number, since it is larger than the sum of its proper divisors (1).

79071721 is an equidigital number, since it uses as much as digits as its factorization.

79071721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6174, while the sum is 34.

The square root of 79071721 is about 8892.2281234795. The cubic root of 79071721 is about 429.2138529490.

The spelling of 79071721 in words is "seventy-nine million, seventy-one thousand, seven hundred twenty-one".