3901921 has 8 divisors (see below), whose sum is σ = 4066920. Its totient is φ = 3739008.

The previous prime is 3901907. The next prime is 3901943. The reversal of 3901921 is 1291093.

It can be written as a sum of positive squares in 4 ways, for example, as 1079521 + 2822400 = 1039^2 + 1680^2 .

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 3901921 - 2¹⁵ = 3869153 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 (3901901) 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, 4125 + ... + 4981.

It is an arithmetic number, because the mean of its divisors is an integer number (508365).

Almost surely, 2^3901921 is an apocalyptic number.

It is an amenable number.

3901921 is a deficient number, since it is larger than the sum of its proper divisors (164999).

3901921 is a wasteful number, since it uses less digits than its factorization.

3901921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 3901921 is about 1975.3280740171. The cubic root of 3901921 is about 157.4319316178.

The spelling of 3901921 in words is "three million, nine hundred one thousand, nine hundred twenty-one".