7687621721 has 8 divisors (see below), whose sum is σ = 8328554304. Its totient is φ = 7053771600.

The previous prime is 7687621717. The next prime is 7687621723. The reversal of 7687621721 is 1271267867.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7687621721 - 2² = 7687621717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7687621723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1768355 + ... + 1772696.

It is an arithmetic number, because the mean of its divisors is an integer number (1041069288).

Almost surely, 2^7687621721 is an apocalyptic number.

It is an amenable number.

7687621721 is a deficient number, since it is larger than the sum of its proper divisors (640932583).

7687621721 is a wasteful number, since it uses less digits than its factorization.

7687621721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3541231.

The product of its digits is 395136, while the sum is 47.

The square root of 7687621721 is about 87679.0837144185. The cubic root of 7687621721 is about 1973.6221096635.

The spelling of 7687621721 in words is "seven billion, six hundred eighty-seven million, six hundred twenty-one thousand, seven hundred twenty-one".