76999999981 has 2 divisors, whose sum is σ = 76999999982. Its totient is φ = 76999999980.

The previous prime is 76999999943. The next prime is 77000000023. The reversal of 76999999981 is 18999999967.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67150429956 + 9849570025 = 259134^2 + 99245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-76999999981 is a prime.

It is a super-2 number, since 2×76999999981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (76999919981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38499999990 + 38499999991.

It is an arithmetic number, because the mean of its divisors is an integer number (38499999991).

Almost surely, 2^76999999981 is an apocalyptic number.

It is an amenable number.

76999999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

76999999981 is an equidigital number, since it uses as much as digits as its factorization.

76999999981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1607077584, while the sum is 85.

The spelling of 76999999981 in words is "seventy-six billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".