76421721809 has 4 divisors (see below), whose sum is σ = 77498084160. Its totient is φ = 75345359460.

The previous prime is 76421721781. The next prime is 76421721821. The reversal of 76421721809 is 90812712467.

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 76421721809 - 2²⁰ = 76420673233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76421721829) 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, 538181069 + ... + 538181210.

It is an arithmetic number, because the mean of its divisors is an integer number (19374521040).

Almost surely, 2^76421721809 is an apocalyptic number.

It is an amenable number.

76421721809 is a deficient number, since it is larger than the sum of its proper divisors (1076362351).

76421721809 is a wasteful number, since it uses less digits than its factorization.

76421721809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076362350.

The product of its (nonzero) digits is 338688, while the sum is 47.

The spelling of 76421721809 in words is "seventy-six billion, four hundred twenty-one million, seven hundred twenty-one thousand, eight hundred nine".