77531461660 has 48 divisors (see below), whose sum is σ = 167130532800. Its totient is φ = 30193896960.

The previous prime is 77531461639. The next prime is 77531461663. The reversal of 77531461660 is 6616413577.

It is a super-2 number, since 2×77531461660² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77531461660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77531461663) 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, 302266 + ... + 496414.

It is an arithmetic number, because the mean of its divisors is an integer number (3481886100).

Almost surely, 2^77531461660 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 77531461660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83565266400).

77531461660 is an abundant number, since it is smaller than the sum of its proper divisors (89599071140).

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

77531461660 is a wasteful number, since it uses less digits than its factorization.

77531461660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194686 (or 194684 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 46.

The spelling of 77531461660 in words is "seventy-seven billion, five hundred thirty-one million, four hundred sixty-one thousand, six hundred sixty".