3515222721 has 16 divisors (see below), whose sum is σ = 4778113536. Its totient is φ = 2297957376.

The previous prime is 3515222693. The next prime is 3515222761. The reversal of 3515222721 is 1272225153.

It is not a de Polignac number, because 3515222721 - 2⁶ = 3515222657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3515222761) 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, 330736 + ... + 341198.

It is an arithmetic number, because the mean of its divisors is an integer number (298632096).

Almost surely, 2^3515222721 is an apocalyptic number.

It is an amenable number.

3515222721 is a deficient number, since it is larger than the sum of its proper divisors (1262890815).

3515222721 is a wasteful number, since it uses less digits than its factorization.

3515222721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12632.

The product of its digits is 8400, while the sum is 30.

The square root of 3515222721 is about 59289.3137167230. The cubic root of 3515222721 is about 1520.4924998304.

Adding to 3515222721 its reverse (1272225153), we get a palindrome (4787447874).

The spelling of 3515222721 in words is "three billion, five hundred fifteen million, two hundred twenty-two thousand, seven hundred twenty-one".