77531328 has 252 divisors, whose sum is σ = 268769592. Its totient is φ = 21288960.

The previous prime is 77531323. The next prime is 77531347. The reversal of 77531328 is 82313577.

It is a tau number, because it is divible by the number of its divisors (252).

It is a super-2 number, since 2×77531328² = 12022213642887168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (35280) is a multiple of the sum of its prime divisors (120).

It is a junction number, because it is equal to n+sod(n) for n = 77531292 and 77531301.

It is not an unprimeable number, because it can be changed into a prime (77531323) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1157151 + ... + 1157217.

It is an arithmetic number, because the mean of its divisors is an integer number (1066546).

Almost surely, 2^77531328 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 77531328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134384796).

77531328 is an abundant number, since it is smaller than the sum of its proper divisors (191238264).

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

77531328 is a wasteful number, since it uses less digits than its factorization.

77531328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 120 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 77531328 is about 8805.1875618865. The cubic root of 77531328 is about 426.4083896940.

The spelling of 77531328 in words is "seventy-seven million, five hundred thirty-one thousand, three hundred twenty-eight".