2090861 has 4 divisors (see below), whose sum is σ = 2181792. Its totient is φ = 1999932.

The previous prime is 2090849. The next prime is 2090863. The reversal of 2090861 is 1680902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1680902 = 2 ⋅840451.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2090861 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2090861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2090863) 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, 45431 + ... + 45476.

It is an arithmetic number, because the mean of its divisors is an integer number (545448).

2^2090861 is an apocalyptic number.

It is an amenable number.

2090861 is a deficient number, since it is larger than the sum of its proper divisors (90931).

2090861 is an equidigital number, since it uses as much as digits as its factorization.

2090861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90930.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 2090861 is about 1445.9809818943. The cubic root of 2090861 is about 127.8718810822.

The spelling of 2090861 in words is "two million, ninety thousand, eight hundred sixty-one".