77915923 has 2 divisors, whose sum is σ = 77915924. Its totient is φ = 77915922.

The previous prime is 77915921. The next prime is 77915933. The reversal of 77915923 is 32951977.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77915923 - 2¹ = 77915921 is a prime.

Together with 77915921, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 77915923.

It is not a weakly prime, because it can be changed into another prime (77915921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38957961 + 38957962.

It is an arithmetic number, because the mean of its divisors is an integer number (38957962).

Almost surely, 2^77915923 is an apocalyptic number.

77915923 is a deficient number, since it is larger than the sum of its proper divisors (1).

77915923 is an equidigital number, since it uses as much as digits as its factorization.

77915923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 119070, while the sum is 43.

The square root of 77915923 is about 8826.9996601337. Note that the first 3 decimals coincide. The cubic root of 77915923 is about 427.1122948900.

The spelling of 77915923 in words is "seventy-seven million, nine hundred fifteen thousand, nine hundred twenty-three".