77781923 has 2 divisors, whose sum is σ = 77781924. Its totient is φ = 77781922.

The previous prime is 77781889. The next prime is 77781931. The reversal of 77781923 is 32918777.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77781923 - 2⁶ = 77781859 is a prime.

It is not a weakly prime, because it can be changed into another prime (77781983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38890961 + 38890962.

It is an arithmetic number, because the mean of its divisors is an integer number (38890962).

Almost surely, 2^77781923 is an apocalyptic number.

77781923 is a deficient number, since it is larger than the sum of its proper divisors (1).

77781923 is an equidigital number, since it uses as much as digits as its factorization.

77781923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 44.

The square root of 77781923 is about 8819.4060457607. The cubic root of 77781923 is about 426.8673047924.

The spelling of 77781923 in words is "seventy-seven million, seven hundred eighty-one thousand, nine hundred twenty-three".