3947621 has 8 divisors (see below), whose sum is σ = 4238424. Its totient is φ = 3663360.

The previous prime is 3947597. The next prime is 3947623. The reversal of 3947621 is 1267493.

It can be written as a sum of positive squares in 4 ways, for example, as 390625 + 3556996 = 625^2 + 1886^2 .

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 3947621 - 2⁶ = 3947557 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 (3947623) 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, 350 + ... + 2831.

It is an arithmetic number, because the mean of its divisors is an integer number (529803).

Almost surely, 2^3947621 is an apocalyptic number.

It is an amenable number.

3947621 is a deficient number, since it is larger than the sum of its proper divisors (290803).

3947621 is a wasteful number, since it uses less digits than its factorization.

3947621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3271.

The product of its digits is 9072, while the sum is 32.

The square root of 3947621 is about 1986.8620988886. The cubic root of 3947621 is about 158.0441712745.

The spelling of 3947621 in words is "three million, nine hundred forty-seven thousand, six hundred twenty-one".