7155560721 has 16 divisors (see below), whose sum is σ = 10314324800. Its totient is φ = 4397156928.

The previous prime is 7155560707. The next prime is 7155560743. The reversal of 7155560721 is 1270655517.

It is not a de Polignac number, because 7155560721 - 2¹⁹ = 7155036433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7155560721.

It is not an unprimeable number, because it can be changed into a prime (7155560221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1694326 + ... + 1698543.

It is an arithmetic number, because the mean of its divisors is an integer number (644645300).

Almost surely, 2^7155560721 is an apocalyptic number.

It is an amenable number.

7155560721 is a deficient number, since it is larger than the sum of its proper divisors (3158764079).

7155560721 is a wasteful number, since it uses less digits than its factorization.

7155560721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3392928.

The product of its (nonzero) digits is 73500, while the sum is 39.

The square root of 7155560721 is about 84590.5474683785. The cubic root of 7155560721 is about 1926.9978220776.

The spelling of 7155560721 in words is "seven billion, one hundred fifty-five million, five hundred sixty thousand, seven hundred twenty-one".