2261991 has 8 divisors (see below), whose sum is σ = 3024000. Its totient is φ = 1503992.

The previous prime is 2261933. The next prime is 2261993. The reversal of 2261991 is 1991622.

It is a happy number.

2261991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2261991 - 2⁶ = 2261927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2261993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 760 + ... + 2258.

It is an arithmetic number, because the mean of its divisors is an integer number (378000).

2^2261991 is an apocalyptic number.

2261991 is a deficient number, since it is larger than the sum of its proper divisors (762009).

2261991 is a wasteful number, since it uses less digits than its factorization.

2261991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2005.

The product of its digits is 1944, while the sum is 30.

The square root of 2261991 is about 1503.9916888068. The cubic root of 2261991 is about 131.2694374841.

The spelling of 2261991 in words is "two million, two hundred sixty-one thousand, nine hundred ninety-one".