77643425 has 12 divisors (see below), whose sum is σ = 97164540. Its totient is φ = 61542720.

The previous prime is 77643421. The next prime is 77643439. The reversal of 77643425 is 52434677.

It can be written as a sum of positive squares in 6 ways, for example, as 44944 + 77598481 = 212^2 + 8809^2 .

It is not a de Polignac number, because 77643425 - 2² = 77643421 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77643421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11522 + ... + 16971.

It is an arithmetic number, because the mean of its divisors is an integer number (8097045).

Almost surely, 2^77643425 is an apocalyptic number.

It is an amenable number.

77643425 is a deficient number, since it is larger than the sum of its proper divisors (19521115).

77643425 is a wasteful number, since it uses less digits than its factorization.

77643425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28612 (or 28607 counting only the distinct ones).

The product of its digits is 141120, while the sum is 38.

The square root of 77643425 is about 8811.5506580851. The cubic root of 77643425 is about 426.6137951928.

The spelling of 77643425 in words is "seventy-seven million, six hundred forty-three thousand, four hundred twenty-five".