2545821 has 6 divisors (see below), whose sum is σ = 3677310. Its totient is φ = 1697208.

The previous prime is 2545817. The next prime is 2545843. The reversal of 2545821 is 1285452.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1664100 + 881721 = 1290^2 + 939^2 .

It is not a de Polignac number, because 2545821 - 2² = 2545817 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2545811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 141426 + ... + 141443.

It is an arithmetic number, because the mean of its divisors is an integer number (612885).

2^2545821 is an apocalyptic number.

It is an amenable number.

2545821 is a deficient number, since it is larger than the sum of its proper divisors (1131489).

2545821 is a wasteful number, since it uses less digits than its factorization.

2545821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282875 (or 282872 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 2545821 is about 1595.5629100728. The cubic root of 2545821 is about 136.5450481271.

The spelling of 2545821 in words is "two million, five hundred forty-five thousand, eight hundred twenty-one".