77561504 has 48 divisors (see below), whose sum is σ = 161554176. Its totient is φ = 36595200.

The previous prime is 77561447. The next prime is 77561537. The reversal of 77561504 is 40516577.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39719 + ... + 41625.

It is an arithmetic number, because the mean of its divisors is an integer number (3365712).

Almost surely, 2^77561504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77561504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80777088).

77561504 is an abundant number, since it is smaller than the sum of its proper divisors (83992672).

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

77561504 is a wasteful number, since it uses less digits than its factorization.

77561504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1989 (or 1981 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 77561504 is about 8806.9009305203. The cubic root of 77561504 is about 426.4637033798.

The spelling of 77561504 in words is "seventy-seven million, five hundred sixty-one thousand, five hundred four".