3991901 has 8 divisors (see below), whose sum is σ = 4190208. Its totient is φ = 3798000.

The previous prime is 3991891. The next prime is 3991943. The reversal of 3991901 is 1091993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3991901 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991961) 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, 836 + ... + 2946.

It is an arithmetic number, because the mean of its divisors is an integer number (523776).

Almost surely, 2^3991901 is an apocalyptic number.

3991901 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3991901 is a deficient number, since it is larger than the sum of its proper divisors (198307).

3991901 is a wasteful number, since it uses less digits than its factorization.

3991901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2203.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 3991901 is about 1997.9742240580. The cubic root of 3991901 is about 158.6328964646.

The spelling of 3991901 in words is "three million, nine hundred ninety-one thousand, nine hundred one".