77161728 has 144 divisors (see below), whose sum is σ = 242794496. Its totient is φ = 21288960.

The previous prime is 77161723. The next prime is 77161739. The reversal of 77161728 is 82716177.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77161723) 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, 166425 + ... + 166887.

Almost surely, 2^77161728 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 77161728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121397248).

77161728 is an abundant number, since it is smaller than the sum of its proper divisors (165632768).

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

77161728 is a wasteful number, since it uses less digits than its factorization.

77161728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520 (or 506 counting only the distinct ones).

The product of its digits is 32928, while the sum is 39.

The square root of 77161728 is about 8784.1748616475. The cubic root of 77161728 is about 425.7297322487.

The spelling of 77161728 in words is "seventy-seven million, one hundred sixty-one thousand, seven hundred twenty-eight".