80662721 has 2 divisors, whose sum is σ = 80662722. Its totient is φ = 80662720.

The previous prime is 80662697. The next prime is 80662787. The reversal of 80662721 is 12726608.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43890625 + 36772096 = 6625^2 + 6064^2 .

It is a cyclic number.

It is not a de Polignac number, because 80662721 - 2²² = 76468417 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (80662121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40331360 + 40331361.

It is an arithmetic number, because the mean of its divisors is an integer number (40331361).

Almost surely, 2^80662721 is an apocalyptic number.

It is an amenable number.

80662721 is a deficient number, since it is larger than the sum of its proper divisors (1).

80662721 is an equidigital number, since it uses as much as digits as its factorization.

80662721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 80662721 is about 8981.2427313819. The cubic root of 80662721 is about 432.0734917979.

The spelling of 80662721 in words is "eighty million, six hundred sixty-two thousand, seven hundred twenty-one".