772799981 has 2 divisors, whose sum is σ = 772799982. Its totient is φ = 772799980.

The previous prime is 772799947. The next prime is 772799987. The reversal of 772799981 is 189997277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490223881 + 282576100 = 22141^2 + 16810^2 .

It is an emirp because it is prime and its reverse (189997277) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 772799981 - 2¹⁴ = 772783597 is a prime.

It is a super-2 number, since 2×772799981² = 1194439621267200722, which contains 22 as substring.

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 772799981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (772799987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 386399990 + 386399991.

It is an arithmetic number, because the mean of its divisors is an integer number (386399991).

Almost surely, 2^772799981 is an apocalyptic number.

It is an amenable number.

772799981 is a deficient number, since it is larger than the sum of its proper divisors (1).

772799981 is an equidigital number, since it uses as much as digits as its factorization.

772799981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4000752, while the sum is 59.

The square root of 772799981 is about 27799.2802244950. The cubic root of 772799981 is about 917.6752826345.

The spelling of 772799981 in words is "seven hundred seventy-two million, seven hundred ninety-nine thousand, nine hundred eighty-one".