1991241 has 12 divisors (see below), whose sum is σ = 3287232. Its totient is φ = 1137816.

The previous prime is 1991239. The next prime is 1991243. The reversal of 1991241 is 1421991.

It is an interprime number because it is at equal distance from previous prime (1991239) and next prime (1991243).

It is not a de Polignac number, because 1991241 - 2¹ = 1991239 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1991243) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15741 + ... + 15866.

It is an arithmetic number, because the mean of its divisors is an integer number (273936).

2^1991241 is an apocalyptic number.

It is an amenable number.

1991241 is a deficient number, since it is larger than the sum of its proper divisors (1295991).

1991241 is a wasteful number, since it uses less digits than its factorization.

1991241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31620 (or 31617 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 1991241 is about 1411.1133901994. The cubic root of 1991241 is about 125.8079083562.

The spelling of 1991241 in words is "one million, nine hundred ninety-one thousand, two hundred forty-one".