77388761 has 2 divisors, whose sum is σ = 77388762. Its totient is φ = 77388760.

The previous prime is 77388757. The next prime is 77388763. The reversal of 77388761 is 16788377.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76457536 + 931225 = 8744^2 + 965^2 .

It is a cyclic number.

It is not a de Polignac number, because 77388761 - 2² = 77388757 is a prime.

Together with 77388763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (77388763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38694380 + 38694381.

It is an arithmetic number, because the mean of its divisors is an integer number (38694381).

Almost surely, 2^77388761 is an apocalyptic number.

It is an amenable number.

77388761 is a deficient number, since it is larger than the sum of its proper divisors (1).

77388761 is an equidigital number, since it uses as much as digits as its factorization.

77388761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 395136, while the sum is 47.

The square root of 77388761 is about 8797.0882114481. The cubic root of 77388761 is about 426.1468650239.

The spelling of 77388761 in words is "seventy-seven million, three hundred eighty-eight thousand, seven hundred sixty-one".