77861731 has 2 divisors, whose sum is σ = 77861732. Its totient is φ = 77861730.

The previous prime is 77861713. The next prime is 77861737. The reversal of 77861731 is 13716877.

Together with previous prime (77861713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77861731 - 2⁵ = 77861699 is a prime.

It is a super-2 number, since 2×77861731² = 12124898308632722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77861737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38930865 + 38930866.

It is an arithmetic number, because the mean of its divisors is an integer number (38930866).

Almost surely, 2^77861731 is an apocalyptic number.

77861731 is a deficient number, since it is larger than the sum of its proper divisors (1).

77861731 is an equidigital number, since it uses as much as digits as its factorization.

77861731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 49392, while the sum is 40.

The square root of 77861731 is about 8823.9294534805. The cubic root of 77861731 is about 427.0132503608.

The spelling of 77861731 in words is "seventy-seven million, eight hundred sixty-one thousand, seven hundred thirty-one".