77742131 has 2 divisors, whose sum is σ = 77742132. Its totient is φ = 77742130.

The previous prime is 77742113. The next prime is 77742163. The reversal of 77742131 is 13124777.

Together with previous prime (77742113) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (77742163) can be obtained adding 77742131 to its sum of digits (32).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77742131 - 2²² = 73547827 is a prime.

It is a super-2 number, since 2×77742131² = 12087677864842322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (77742101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38871065 + 38871066.

It is an arithmetic number, because the mean of its divisors is an integer number (38871066).

Almost surely, 2^77742131 is an apocalyptic number.

77742131 is a deficient number, since it is larger than the sum of its proper divisors (1).

77742131 is an equidigital number, since it uses as much as digits as its factorization.

77742131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8232, while the sum is 32.

The square root of 77742131 is about 8817.1498229303. The cubic root of 77742131 is about 426.7944995246.

The spelling of 77742131 in words is "seventy-seven million, seven hundred forty-two thousand, one hundred thirty-one".