77281691 has 2 divisors, whose sum is σ = 77281692. Its totient is φ = 77281690.

The previous prime is 77281661. The next prime is 77281703. The reversal of 77281691 is 19618277.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77281691 - 2²² = 73087387 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77281601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38640845 + 38640846.

It is an arithmetic number, because the mean of its divisors is an integer number (38640846).

Almost surely, 2^77281691 is an apocalyptic number.

77281691 is a deficient number, since it is larger than the sum of its proper divisors (1).

77281691 is an equidigital number, since it uses as much as digits as its factorization.

77281691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 41.

The square root of 77281691 is about 8791.0005687635. Note that the first 3 decimals coincide. The cubic root of 77281691 is about 425.9502447272.

The spelling of 77281691 in words is "seventy-seven million, two hundred eighty-one thousand, six hundred ninety-one".