3981921637 has 8 divisors (see below), whose sum is σ = 4192139360. Its totient is φ = 3771768240.

The previous prime is 3981921631. The next prime is 3981921653. The reversal of 3981921637 is 7361291893.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3981921637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981921631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161203 + ... + 184255.

It is an arithmetic number, because the mean of its divisors is an integer number (524017420).

Almost surely, 2^3981921637 is an apocalyptic number.

It is an amenable number.

3981921637 is a deficient number, since it is larger than the sum of its proper divisors (210217723).

3981921637 is a wasteful number, since it uses less digits than its factorization.

3981921637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32163.

The product of its digits is 489888, while the sum is 49.

The square root of 3981921637 is about 63102.4693415400. The cubic root of 3981921637 is about 1585.0059723725.

The spelling of 3981921637 in words is "three billion, nine hundred eighty-one million, nine hundred twenty-one thousand, six hundred thirty-seven".