2566921 has 4 divisors (see below), whose sum is σ = 2933632. Its totient is φ = 2200212.

The previous prime is 2566909. The next prime is 2566931. The reversal of 2566921 is 1296652.

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.

It is not a de Polignac number, because 2566921 - 2¹³ = 2558729 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2566931) 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, 183345 + ... + 183358.

It is an arithmetic number, because the mean of its divisors is an integer number (733408).

2^2566921 is an apocalyptic number.

It is an amenable number.

2566921 is a deficient number, since it is larger than the sum of its proper divisors (366711).

2566921 is an equidigital number, since it uses as much as digits as its factorization.

2566921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366710.

The product of its digits is 6480, while the sum is 31.

The square root of 2566921 is about 1602.1613526733. The cubic root of 2566921 is about 136.9212433839.

The spelling of 2566921 in words is "two million, five hundred sixty-six thousand, nine hundred twenty-one".