77512081 has 8 divisors (see below), whose sum is σ = 78255720. Its totient is φ = 76772352.

The previous prime is 77512069. The next prime is 77512087. The reversal of 77512081 is 18021577.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3207681 + 74304400 = 1791^2 + 8620^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77512081 - 2⁷ = 77511953 is a prime.

It is a super-2 number, since 2×77512081² = 12016245401901122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77512087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51171 + ... + 52663.

It is an arithmetic number, because the mean of its divisors is an integer number (9781965).

Almost surely, 2^77512081 is an apocalyptic number.

It is an amenable number.

77512081 is a deficient number, since it is larger than the sum of its proper divisors (743639).

77512081 is a wasteful number, since it uses less digits than its factorization.

77512081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1955.

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 77512081 is about 8804.0945587834. The cubic root of 77512081 is about 426.3731017585.

The spelling of 77512081 in words is "seventy-seven million, five hundred twelve thousand, eighty-one".