77981933 has 2 divisors, whose sum is σ = 77981934. Its totient is φ = 77981932.

The previous prime is 77981923. The next prime is 77981951. The reversal of 77981933 is 33918977.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73324969 + 4656964 = 8563^2 + 2158^2 .

It is an emirp because it is prime and its reverse (33918977) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77981933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77981923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38990966 + 38990967.

It is an arithmetic number, because the mean of its divisors is an integer number (38990967).

Almost surely, 2^77981933 is an apocalyptic number.

It is an amenable number.

77981933 is a deficient number, since it is larger than the sum of its proper divisors (1).

77981933 is an equidigital number, since it uses as much as digits as its factorization.

77981933 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 47.

The square root of 77981933 is about 8830.7379646324. The cubic root of 77981933 is about 427.2328766804.

The spelling of 77981933 in words is "seventy-seven million, nine hundred eighty-one thousand, nine hundred thirty-three".