77138749 has 2 divisors, whose sum is σ = 77138750. Its totient is φ = 77138748.

The previous prime is 77138701. The next prime is 77138759. The reversal of 77138749 is 94783177.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69056100 + 8082649 = 8310^2 + 2843^2 .

It is a cyclic number.

It is not a de Polignac number, because 77138749 - 2¹⁵ = 77105981 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 77138699 and 77138708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77138759) 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, 38569374 + 38569375.

It is an arithmetic number, because the mean of its divisors is an integer number (38569375).

Almost surely, 2^77138749 is an apocalyptic number.

It is an amenable number.

77138749 is a deficient number, since it is larger than the sum of its proper divisors (1).

77138749 is an equidigital number, since it uses as much as digits as its factorization.

77138749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 296352, while the sum is 46.

The square root of 77138749 is about 8782.8667871032. The cubic root of 77138749 is about 425.6874668448.

The spelling of 77138749 in words is "seventy-seven million, one hundred thirty-eight thousand, seven hundred forty-nine".