77661908 has 12 divisors (see below), whose sum is σ = 136001460. Its totient is φ = 38804352.

The previous prime is 77661901. The next prime is 77661919. The reversal of 77661908 is 80916677.

It can be written as a sum of positive squares in 2 ways, for example, as 47169424 + 30492484 = 6868^2 + 5522^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77661901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 860 + ... + 12492.

It is an arithmetic number, because the mean of its divisors is an integer number (11333455).

Almost surely, 2^77661908 is an apocalyptic number.

It is an amenable number.

77661908 is a deficient number, since it is larger than the sum of its proper divisors (58339552).

77661908 is a wasteful number, since it uses less digits than its factorization.

77661908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13306 (or 13304 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 77661908 is about 8812.5993895105. The cubic root of 77661908 is about 426.6476442800.

The spelling of 77661908 in words is "seventy-seven million, six hundred sixty-one thousand, nine hundred eight".