80051981 has 2 divisors, whose sum is σ = 80051982. Its totient is φ = 80051980.

The previous prime is 80051971. The next prime is 80052017. The reversal of 80051981 is 18915008.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71402500 + 8649481 = 8450^2 + 2941^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80051981 is a prime.

It is a super-2 number, since 2×80051981² = 12816639324048722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80051911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40025990 + 40025991.

It is an arithmetic number, because the mean of its divisors is an integer number (40025991).

Almost surely, 2^80051981 is an apocalyptic number.

It is an amenable number.

80051981 is a deficient number, since it is larger than the sum of its proper divisors (1).

80051981 is an equidigital number, since it uses as much as digits as its factorization.

80051981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 32.

The square root of 80051981 is about 8947.1772643667. The cubic root of 80051981 is about 430.9802425254.

Adding to 80051981 its reverse (18915008), we get a palindrome (98966989).

The spelling of 80051981 in words is "eighty million, fifty-one thousand, nine hundred eighty-one".