2159491 has 4 divisors (see below), whose sum is σ = 2229184. Its totient is φ = 2089800.

The previous prime is 2159473. The next prime is 2159497. The reversal of 2159491 is 1949512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2159491 - 2⁷ = 2159363 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 69661 = 2159491 / (2 + 1 + 5 + 9 + 4 + 9 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2159497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34800 + ... + 34861.

It is an arithmetic number, because the mean of its divisors is an integer number (557296).

2^2159491 is an apocalyptic number.

2159491 is a deficient number, since it is larger than the sum of its proper divisors (69693).

2159491 is an equidigital number, since it uses as much as digits as its factorization.

2159491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69692.

The product of its digits is 3240, while the sum is 31.

The square root of 2159491 is about 1469.5206701506. The cubic root of 2159491 is about 129.2559268333.

The spelling of 2159491 in words is "two million, one hundred fifty-nine thousand, four hundred ninety-one".