77113521 has 6 divisors (see below), whose sum is σ = 111386210. Its totient is φ = 51409008.

The previous prime is 77113501. The next prime is 77113567. The reversal of 77113521 is 12531177.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 77000625 + 112896 = 8775^2 + 336^2 .

It is not a de Polignac number, because 77113521 - 2⁹ = 77113009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77113501) 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 5 ways as a sum of consecutive naturals, for example, 4284076 + ... + 4284093.

Almost surely, 2^77113521 is an apocalyptic number.

It is an amenable number.

77113521 is a deficient number, since it is larger than the sum of its proper divisors (34272689).

77113521 is a wasteful number, since it uses less digits than its factorization.

77113521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8568175 (or 8568172 counting only the distinct ones).

The product of its digits is 1470, while the sum is 27.

The square root of 77113521 is about 8781.4304643378. The cubic root of 77113521 is about 425.6410551753.

Adding to 77113521 its reverse (12531177), we get a palindrome (89644698).

The spelling of 77113521 in words is "seventy-seven million, one hundred thirteen thousand, five hundred twenty-one".