76747721 has 4 divisors (see below), whose sum is σ = 76829712. Its totient is φ = 76665732.

The previous prime is 76747709. The next prime is 76747729. The reversal of 76747721 is 12774767.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 76747721 - 2²² = 72553417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (76747729) 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, 39575 + ... + 41468.

It is an arithmetic number, because the mean of its divisors is an integer number (19207428).

Almost surely, 2^76747721 is an apocalyptic number.

It is an amenable number.

76747721 is a deficient number, since it is larger than the sum of its proper divisors (81991).

76747721 is an equidigital number, since it uses as much as digits as its factorization.

76747721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81990.

The product of its digits is 115248, while the sum is 41.

The square root of 76747721 is about 8760.5776636019. The cubic root of 76747721 is about 424.9669566005.

The spelling of 76747721 in words is "seventy-six million, seven hundred forty-seven thousand, seven hundred twenty-one".