77869991 has 2 divisors, whose sum is σ = 77869992. Its totient is φ = 77869990.

The previous prime is 77869969. The next prime is 77870027. The reversal of 77869991 is 19996877.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77869991 - 2²² = 73675687 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77869921) 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, 38934995 + 38934996.

It is an arithmetic number, because the mean of its divisors is an integer number (38934996).

Almost surely, 2^77869991 is an apocalyptic number.

77869991 is a deficient number, since it is larger than the sum of its proper divisors (1).

77869991 is an equidigital number, since it uses as much as digits as its factorization.

77869991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 56.

The square root of 77869991 is about 8824.3974865143. The cubic root of 77869991 is about 427.0283497970.

The spelling of 77869991 in words is "seventy-seven million, eight hundred sixty-nine thousand, nine hundred ninety-one".