3981921724 has 36 divisors (see below), whose sum is σ = 7674627744. Its totient is φ = 1806376000.

The previous prime is 3981921701. The next prime is 3981921739. The reversal of 3981921724 is 4271291893.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 244269 + ... + 260059.

It is an arithmetic number, because the mean of its divisors is an integer number (213184104).

Almost surely, 2^3981921724 is an apocalyptic number.

It is an amenable number.

3981921724 is a deficient number, since it is larger than the sum of its proper divisors (3692706020).

3981921724 is a wasteful number, since it uses less digits than its factorization.

3981921724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16338 (or 16325 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The square root of 3981921724 is about 63102.4700308950. The cubic root of 3981921724 is about 1585.0059839159.

The spelling of 3981921724 in words is "three billion, nine hundred eighty-one million, nine hundred twenty-one thousand, seven hundred twenty-four".