2553821 has 4 divisors (see below), whose sum is σ = 2557500. Its totient is φ = 2550144.

The previous prime is 2553797. The next prime is 2553823. The reversal of 2553821 is 1283552.

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

It can be written as a sum of positive squares in 2 ways, for example, as 151321 + 2402500 = 389^2 + 1550^2 .

It is a cyclic number.

It is not a de Polignac number, because 2553821 - 2¹⁸ = 2291677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2553823) 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, 446 + ... + 2303.

It is an arithmetic number, because the mean of its divisors is an integer number (639375).

2^2553821 is an apocalyptic number.

It is an amenable number.

2553821 is a deficient number, since it is larger than the sum of its proper divisors (3679).

2553821 is an equidigital number, since it uses as much as digits as its factorization.

2553821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3678.

The product of its digits is 2400, while the sum is 26.

The square root of 2553821 is about 1598.0678959293. The cubic root of 2553821 is about 136.6879251748.

The spelling of 2553821 in words is "two million, five hundred fifty-three thousand, eight hundred twenty-one".