3581721644 has 24 divisors (see below), whose sum is σ = 6638166528. Its totient is φ = 1687427280.

The previous prime is 3581721641. The next prime is 3581721707. The reversal of 3581721644 is 4461271853.

It is not an unprimeable number, because it can be changed into a prime (3581721641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 284372 + ... + 296699.

It is an arithmetic number, because the mean of its divisors is an integer number (276590272).

Almost surely, 2^3581721644 is an apocalyptic number.

It is an amenable number.

3581721644 is a deficient number, since it is larger than the sum of its proper divisors (3056444884).

3581721644 is a wasteful number, since it uses less digits than its factorization.

3581721644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581165 (or 581163 counting only the distinct ones).

The product of its digits is 161280, while the sum is 41.

The square root of 3581721644 is about 59847.4865303465. The cubic root of 3581721644 is about 1530.0205963594.

The spelling of 3581721644 in words is "three billion, five hundred eighty-one million, seven hundred twenty-one thousand, six hundred forty-four".