2201991 has 16 divisors (see below), whose sum is σ = 3265920. Its totient is φ = 1308320.

The previous prime is 2201989. The next prime is 2202007. The reversal of 2201991 is 1991022.

It is a cyclic number.

It is not a de Polignac number, because 2201991 - 2¹ = 2201989 is a prime.

2201991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2201911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1120 + ... + 2378.

It is an arithmetic number, because the mean of its divisors is an integer number (204120).

2^2201991 is an apocalyptic number.

2201991 is a deficient number, since it is larger than the sum of its proper divisors (1063929).

2201991 is a wasteful number, since it uses less digits than its factorization.

2201991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 2201991 is about 1483.9107115996. The cubic root of 2201991 is about 130.0983673640.

It can be divided in two parts, 220 and 1991, that added together give a triangular number (2211 = T₆₆).

The spelling of 2201991 in words is "two million, two hundred one thousand, nine hundred ninety-one".