3981521 has 8 divisors (see below), whose sum is σ = 4080000. Its totient is φ = 3884400.

The previous prime is 3981517. The next prime is 3981539. The reversal of 3981521 is 1251893.

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

It is a cyclic number.

It is not a de Polignac number, because 3981521 - 2² = 3981517 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3981541) 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, 7730 + ... + 8228.

It is an arithmetic number, because the mean of its divisors is an integer number (510000).

Almost surely, 2^3981521 is an apocalyptic number.

It is an amenable number.

3981521 is a deficient number, since it is larger than the sum of its proper divisors (98479).

3981521 is a wasteful number, since it uses less digits than its factorization.

3981521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679.

The product of its digits is 2160, while the sum is 29.

The square root of 3981521 is about 1995.3749021174. The cubic root of 3981521 is about 158.4952812668.

The spelling of 3981521 in words is "three million, nine hundred eighty-one thousand, five hundred twenty-one".