80639969 has 2 divisors, whose sum is σ = 80639970. Its totient is φ = 80639968.

The previous prime is 80639953. The next prime is 80640011. The reversal of 80639969 is 96993608.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78499600 + 2140369 = 8860^2 + 1463^2 .

It is a cyclic number.

It is not a de Polignac number, because 80639969 - 2⁴ = 80639953 is a prime.

It is a super-2 number, since 2×80639969² = 13005609200641922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (80639929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40319984 + 40319985.

It is an arithmetic number, because the mean of its divisors is an integer number (40319985).

Almost surely, 2^80639969 is an apocalyptic number.

It is an amenable number.

80639969 is a deficient number, since it is larger than the sum of its proper divisors (1).

80639969 is an equidigital number, since it uses as much as digits as its factorization.

80639969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 50.

The square root of 80639969 is about 8979.9760021951. The cubic root of 80639969 is about 432.0328639407.

The spelling of 80639969 in words is "eighty million, six hundred thirty-nine thousand, nine hundred sixty-nine".