80991877 has 2 divisors, whose sum is σ = 80991878. Its totient is φ = 80991876.

The previous prime is 80991839. The next prime is 80991881. The reversal of 80991877 is 77819908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41036836 + 39955041 = 6406^2 + 6321^2 .

It is a cyclic number.

It is not a de Polignac number, because 80991877 - 2¹¹ = 80989829 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 80991877.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80991377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40495938 + 40495939.

It is an arithmetic number, because the mean of its divisors is an integer number (40495939).

Almost surely, 2^80991877 is an apocalyptic number.

It is an amenable number.

80991877 is a deficient number, since it is larger than the sum of its proper divisors (1).

80991877 is an equidigital number, since it uses as much as digits as its factorization.

80991877 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 80991877 is about 8999.5487109077. The cubic root of 80991877 is about 432.6604071602.

The spelling of 80991877 in words is "eighty million, nine hundred ninety-one thousand, eight hundred seventy-seven".