77767891 has 2 divisors, whose sum is σ = 77767892. Its totient is φ = 77767890.

The previous prime is 77767883. The next prime is 77767901. The reversal of 77767891 is 19876777.

It is a weak prime.

It is an emirp because it is prime and its reverse (19876777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77767891 - 2³ = 77767883 is a prime.

It is not a weakly prime, because it can be changed into another prime (77717891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38883945 + 38883946.

It is an arithmetic number, because the mean of its divisors is an integer number (38883946).

Almost surely, 2^77767891 is an apocalyptic number.

77767891 is a deficient number, since it is larger than the sum of its proper divisors (1).

77767891 is an equidigital number, since it uses as much as digits as its factorization.

77767891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1037232, while the sum is 52.

The square root of 77767891 is about 8818.6104914550. The cubic root of 77767891 is about 426.8416340366.

The spelling of 77767891 in words is "seventy-seven million, seven hundred sixty-seven thousand, eight hundred ninety-one".