3521670721 has 2 divisors, whose sum is σ = 3521670722. Its totient is φ = 3521670720.

The previous prime is 3521670707. The next prime is 3521670799. The reversal of 3521670721 is 1270761253.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1828759696 + 1692911025 = 42764^2 + 41145^2 .

It is an emirp because it is prime and its reverse (1270761253) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3521670721 - 2⁵ = 3521670689 is a prime.

It is not a weakly prime, because it can be changed into another prime (3521640721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1760835360 + 1760835361.

It is an arithmetic number, because the mean of its divisors is an integer number (1760835361).

Almost surely, 2^3521670721 is an apocalyptic number.

It is an amenable number.

3521670721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3521670721 is an equidigital number, since it uses as much as digits as its factorization.

3521670721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 3521670721 is about 59343.6662247961. Note that the first 3 decimals coincide. The cubic root of 3521670721 is about 1521.4216156521.

The spelling of 3521670721 in words is "three billion, five hundred twenty-one million, six hundred seventy thousand, seven hundred twenty-one".