3903721 has 8 divisors (see below), whose sum is σ = 4288320. Its totient is φ = 3537072.

The previous prime is 3903703. The next prime is 3903749. The reversal of 3903721 is 1273093.

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 3903721 - 2⁵ = 3903689 is a prime.

It is a Duffinian number.

3903721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3943721) 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, 4030 + ... + 4903.

It is an arithmetic number, because the mean of its divisors is an integer number (536040).

Almost surely, 2^3903721 is an apocalyptic number.

It is an amenable number.

3903721 is a deficient number, since it is larger than the sum of its proper divisors (384599).

3903721 is a wasteful number, since it uses less digits than its factorization.

3903721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8975.

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 3903721 is about 1975.7836420013. The cubic root of 3903721 is about 157.4561362692.

It can be divided in two parts, 3903 and 721, that added together give a square (4624 = 68²).

The spelling of 3903721 in words is "three million, nine hundred three thousand, seven hundred twenty-one".