76440611521 has 4 divisors (see below), whose sum is σ = 76521845844. Its totient is φ = 76359377200.

The previous prime is 76440611479. The next prime is 76440611543. The reversal of 76440611521 is 12511604467.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53377633296 + 23062978225 = 231036^2 + 151865^2 .

It is a cyclic number.

It is not a de Polignac number, because 76440611521 - 2³¹ = 74293127873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76440611551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40615750 + ... + 40617631.

It is an arithmetic number, because the mean of its divisors is an integer number (19130461461).

Almost surely, 2^76440611521 is an apocalyptic number.

It is an amenable number.

76440611521 is a deficient number, since it is larger than the sum of its proper divisors (81234323).

76440611521 is an equidigital number, since it uses as much as digits as its factorization.

76440611521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81234322.

The product of its (nonzero) digits is 40320, while the sum is 37.

The spelling of 76440611521 in words is "seventy-six billion, four hundred forty million, six hundred eleven thousand, five hundred twenty-one".