2520821 has 2 divisors, whose sum is σ = 2520822. Its totient is φ = 2520820.

The previous prime is 2520797. The next prime is 2520829. The reversal of 2520821 is 1280252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2436721 + 84100 = 1561^2 + 290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2520821 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2520793 and 2520802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2520829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1260410 + 1260411.

It is an arithmetic number, because the mean of its divisors is an integer number (1260411).

2^2520821 is an apocalyptic number.

It is an amenable number.

2520821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2520821 is an equidigital number, since it uses as much as digits as its factorization.

2520821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 2520821 is about 1587.7093562740. The cubic root of 2520821 is about 136.0966189145.

The spelling of 2520821 in words is "two million, five hundred twenty thousand, eight hundred twenty-one".