3901221 has 6 divisors (see below), whose sum is σ = 5635110. Its totient is φ = 2600808.

The previous prime is 3901217. The next prime is 3901223. The reversal of 3901221 is 1221093.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2873025 + 1028196 = 1695^2 + 1014^2 .

It is not a de Polignac number, because 3901221 - 2² = 3901217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3901194 and 3901203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3901223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216726 + ... + 216743.

It is an arithmetic number, because the mean of its divisors is an integer number (939185).

Almost surely, 2^3901221 is an apocalyptic number.

It is an amenable number.

3901221 is a deficient number, since it is larger than the sum of its proper divisors (1733889).

3901221 is a wasteful number, since it uses less digits than its factorization.

3901221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433475 (or 433472 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 3901221 is about 1975.1508803127. The cubic root of 3901221 is about 157.4225166874.

The spelling of 3901221 in words is "three million, nine hundred one thousand, two hundred twenty-one".