77613640 has 32 divisors (see below), whose sum is σ = 188065080. Its totient is φ = 28657152.

The previous prime is 77613593. The next prime is 77613647. The reversal of 77613640 is 4631677.

It can be written as a sum of positive squares in 4 ways, for example, as 63968004 + 13645636 = 7998^2 + 3694^2 .

It is a super-2 number, since 2×77613640² = 12047754228099200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 77613596 and 77613605.

It is not an unprimeable number, because it can be changed into a prime (77613647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74109 + ... + 75148.

Almost surely, 2^77613640 is an apocalyptic number.

It is an amenable number.

77613640 is an abundant number, since it is smaller than the sum of its proper divisors (110451440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77613640 is a wasteful number, since it uses less digits than its factorization.

77613640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149281 (or 149277 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 34.

The square root of 77613640 is about 8809.8603848188. The cubic root of 77613640 is about 426.5592367330.

The spelling of 77613640 in words is "seventy-seven million, six hundred thirteen thousand, six hundred forty".