77108981 has 2 divisors, whose sum is σ = 77108982. Its totient is φ = 77108980.

The previous prime is 77108947. The next prime is 77109013. The reversal of 77108981 is 18980177.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69872881 + 7236100 = 8359^2 + 2690^2 .

It is a cyclic number.

It is not a de Polignac number, because 77108981 - 2¹⁰ = 77107957 is a prime.

It is a super-2 number, since 2×77108981² = 11891589901716722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77108281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38554490 + 38554491.

It is an arithmetic number, because the mean of its divisors is an integer number (38554491).

Almost surely, 2^77108981 is an apocalyptic number.

It is an amenable number.

77108981 is a deficient number, since it is larger than the sum of its proper divisors (1).

77108981 is an equidigital number, since it uses as much as digits as its factorization.

77108981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 77108981 is about 8781.1719605073. The cubic root of 77108981 is about 425.6327019133.

The spelling of 77108981 in words is "seventy-seven million, one hundred eight thousand, nine hundred eighty-one".