80972281661 has 2 divisors, whose sum is σ = 80972281662. Its totient is φ = 80972281660.

The previous prime is 80972281619. The next prime is 80972281673. The reversal of 80972281661 is 16618227908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65551360900 + 15420920761 = 256030^2 + 124181^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80972281661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80972289661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40486140830 + 40486140831.

It is an arithmetic number, because the mean of its divisors is an integer number (40486140831).

Almost surely, 2^80972281661 is an apocalyptic number.

It is an amenable number.

80972281661 is a deficient number, since it is larger than the sum of its proper divisors (1).

80972281661 is an equidigital number, since it uses as much as digits as its factorization.

80972281661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 80972281661 in words is "eighty billion, nine hundred seventy-two million, two hundred eighty-one thousand, six hundred sixty-one".