7655472721 has 4 divisors (see below), whose sum is σ = 8244355252. Its totient is φ = 7066590192.

The previous prime is 7655472701. The next prime is 7655472749. The reversal of 7655472721 is 1272745567.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3749847696 + 3905625025 = 61236^2 + 62495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7655472721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7655472701) 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, 294441246 + ... + 294441271.

It is an arithmetic number, because the mean of its divisors is an integer number (2061088813).

Almost surely, 2^7655472721 is an apocalyptic number.

It is an amenable number.

7655472721 is a deficient number, since it is larger than the sum of its proper divisors (588882531).

7655472721 is a wasteful number, since it uses less digits than its factorization.

7655472721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588882530.

The product of its digits is 823200, while the sum is 46.

The square root of 7655472721 is about 87495.5582929785. The cubic root of 7655472721 is about 1970.8670907037.

The spelling of 7655472721 in words is "seven billion, six hundred fifty-five million, four hundred seventy-two thousand, seven hundred twenty-one".