2545781 has 4 divisors (see below), whose sum is σ = 2909472. Its totient is φ = 2182092.

The previous prime is 2545771. The next prime is 2545783. The reversal of 2545781 is 1875452.

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 a cyclic number.

It is not a de Polignac number, because 2545781 - 2¹⁰ = 2544757 is a prime.

It is a super-2 number, since 2×2545781² = 12962001799922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2545783) 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, 181835 + ... + 181848.

It is an arithmetic number, because the mean of its divisors is an integer number (727368).

2^2545781 is an apocalyptic number.

It is an amenable number.

2545781 is a deficient number, since it is larger than the sum of its proper divisors (363691).

2545781 is an equidigital number, since it uses as much as digits as its factorization.

2545781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363690.

The product of its digits is 11200, while the sum is 32.

The square root of 2545781 is about 1595.5503752624. The cubic root of 2545781 is about 136.5443329903.

The spelling of 2545781 in words is "two million, five hundred forty-five thousand, seven hundred eighty-one".