76386721 has 2 divisors, whose sum is σ = 76386722. Its totient is φ = 76386720.

The previous prime is 76386691. The next prime is 76386743. The reversal of 76386721 is 12768367.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39237696 + 37149025 = 6264^2 + 6095^2 .

It is a cyclic number.

It is not a de Polignac number, because 76386721 - 2⁹ = 76386209 is a prime.

It is a super-2 number, since 2×76386721² = 11669862290263682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (76386781) 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 as a sum of consecutive naturals, namely, 38193360 + 38193361.

It is an arithmetic number, because the mean of its divisors is an integer number (38193361).

Almost surely, 2^76386721 is an apocalyptic number.

It is an amenable number.

76386721 is a deficient number, since it is larger than the sum of its proper divisors (1).

76386721 is an equidigital number, since it uses as much as digits as its factorization.

76386721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84672, while the sum is 40.

The square root of 76386721 is about 8739.9497138141. The cubic root of 76386721 is about 424.2996002396.

The spelling of 76386721 in words is "seventy-six million, three hundred eighty-six thousand, seven hundred twenty-one".