3713561721 has 63 divisors (see below), whose sum is σ = 5817690333. Its totient is φ = 2369308320.

The previous prime is 3713561713. The next prime is 3713561741. The reversal of 3713561721 is 1271653173.

The square root of 3713561721 is 60939.

It is a perfect power (a square), and thus also a powerful number.

3713561721 is a `hidden beast` number, since 3 + 7 + 1 + 35 + 617 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 81812025 + 3631749696 = 9045^2 + 60264^2 .

It is not a de Polignac number, because 3713561721 - 2³ = 3713561713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3713561711) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 60878031 + ... + 60878091.

It is an arithmetic number, because the mean of its divisors is an integer number (92344291).

Almost surely, 2^3713561721 is an apocalyptic number.

3713561721 is the 60939-th square number.

3713561721 is the 30470-th centered octagonal number.

It is an amenable number.

3713561721 is a deficient number, since it is larger than the sum of its proper divisors (2104128612).

3713561721 is an frugal number, since it uses more digits than its factorization.

3713561721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 101 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The cubic root of 3713561721 is about 1548.5677676645.

Multiplying 3713561721 by its sum of digits (36), we get a square (133688221956 = 365634²).

The spelling of 3713561721 in words is "three billion, seven hundred thirteen million, five hundred sixty-one thousand, seven hundred twenty-one".