3957621 has 4 divisors (see below), whose sum is σ = 5276832. Its totient is φ = 2638412.

The previous prime is 3957571. The next prime is 3957637. The reversal of 3957621 is 1267593.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3957621 - 2⁷ = 3957493 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3957671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 659601 + ... + 659606.

It is an arithmetic number, because the mean of its divisors is an integer number (1319208).

Almost surely, 2^3957621 is an apocalyptic number.

It is an amenable number.

3957621 is a deficient number, since it is larger than the sum of its proper divisors (1319211).

3957621 is a wasteful number, since it uses less digits than its factorization.

3957621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319210.

The product of its digits is 11340, while the sum is 33.

The square root of 3957621 is about 1989.3770381705. The cubic root of 3957621 is about 158.1775097314.

The spelling of 3957621 in words is "three million, nine hundred fifty-seven thousand, six hundred twenty-one".