77521536 has 80 divisors (see below), whose sum is σ = 230733690. Its totient is φ = 25837056.

The previous prime is 77521531. The next prime is 77521537. The reversal of 77521536 is 63512577.

77521536 is a `hidden beast` number, since 77 + 52 + 1 + 536 = 666.

It can be written as a sum of positive squares in only one way, i.e., 46785600 + 30735936 = 6840^2 + 5544^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 77521536.

It is not an unprimeable number, because it can be changed into a prime (77521531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 6630 + ... + 14106.

Almost surely, 2^77521536 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 77521536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115366845).

77521536 is an abundant number, since it is smaller than the sum of its proper divisors (153212154).

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

77521536 is an equidigital number, since it uses as much as digits as its factorization.

77521536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7503 (or 7482 counting only the distinct ones).

The product of its digits is 44100, while the sum is 36.

The square root of 77521536 is about 8804.6315084733. The cubic root of 77521536 is about 426.3904375240.

The spelling of 77521536 in words is "seventy-seven million, five hundred twenty-one thousand, five hundred thirty-six".