76615404721 has 4 divisors (see below), whose sum is σ = 81122193252. Its totient is φ = 72108616192.

The previous prime is 76615404647. The next prime is 76615404751. The reversal of 76615404721 is 12740451667.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12740451667 = 112577 ⋅113171.

It can be written as a sum of positive squares in 2 ways, for example, as 51765350400 + 24850054321 = 227520^2 + 157639^2 .

It is a cyclic number.

It is not a de Polignac number, because 76615404721 - 2⁹ = 76615404209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76615404751) 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, 2253394240 + ... + 2253394273.

It is an arithmetic number, because the mean of its divisors is an integer number (20280548313).

Almost surely, 2^76615404721 is an apocalyptic number.

It is an amenable number.

76615404721 is a deficient number, since it is larger than the sum of its proper divisors (4506788531).

76615404721 is a wasteful number, since it uses less digits than its factorization.

76615404721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4506788530.

The product of its (nonzero) digits is 282240, while the sum is 43.

The spelling of 76615404721 in words is "seventy-six billion, six hundred fifteen million, four hundred four thousand, seven hundred twenty-one".