76822721 has 4 divisors (see below), whose sum is σ = 77583444. Its totient is φ = 76062000.

The previous prime is 76822717. The next prime is 76822727. The reversal of 76822721 is 12722867.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12722867 = 2861 ⋅4447.

It can be written as a sum of positive squares in 2 ways, for example, as 74632321 + 2190400 = 8639^2 + 1480^2 .

It is a cyclic number.

It is not a de Polignac number, because 76822721 - 2² = 76822717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76822727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380210 + ... + 380411.

It is an arithmetic number, because the mean of its divisors is an integer number (19395861).

Almost surely, 2^76822721 is an apocalyptic number.

It is an amenable number.

76822721 is a deficient number, since it is larger than the sum of its proper divisors (760723).

76822721 is a wasteful number, since it uses less digits than its factorization.

76822721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760722.

The product of its digits is 18816, while the sum is 35.

The square root of 76822721 is about 8764.8571579918. The cubic root of 76822721 is about 425.1053413618.

The spelling of 76822721 in words is "seventy-six million, eight hundred twenty-two thousand, seven hundred twenty-one".