77539649 has 16 divisors (see below), whose sum is σ = 90339840. Its totient is φ = 65856000.

The previous prime is 77539643. The next prime is 77539661. The reversal of 77539649 is 94693577.

It is a cyclic number.

It is not a de Polignac number, because 77539649 - 2⁴ = 77539633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 77539597 and 77539606.

It is not an unprimeable number, because it can be changed into a prime (77539643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5969 + ... + 13809.

It is an arithmetic number, because the mean of its divisors is an integer number (5646240).

Almost surely, 2^77539649 is an apocalyptic number.

It is an amenable number.

77539649 is a deficient number, since it is larger than the sum of its proper divisors (12800191).

77539649 is a wasteful number, since it uses less digits than its factorization.

77539649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7912.

The product of its digits is 1428840, while the sum is 50.

The square root of 77539649 is about 8805.6600547602. The cubic root of 77539649 is about 426.4236438172.

The spelling of 77539649 in words is "seventy-seven million, five hundred thirty-nine thousand, six hundred forty-nine".