2645521 has 2 divisors, whose sum is σ = 2645522. Its totient is φ = 2645520.

The previous prime is 2645519. The next prime is 2645527. The reversal of 2645521 is 1255462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2359296 + 286225 = 1536^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 2645521 - 2¹ = 2645519 is a prime.

It is a super-2 number, since 2×2645521² = 13997562722882, which contains 22 as substring.

Together with 2645519, it forms a pair of twin primes.

2645521 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2645527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322760 + 1322761.

It is an arithmetic number, because the mean of its divisors is an integer number (1322761).

2^2645521 is an apocalyptic number.

It is an amenable number.

2645521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2645521 is an equidigital number, since it uses as much as digits as its factorization.

2645521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 25.

The square root of 2645521 is about 1626.5057639000. The cubic root of 2645521 is about 138.3047420790.

It can be divided in two parts, 26455 and 21, that multiplied together give a palindrome (555555).

The spelling of 2645521 in words is "two million, six hundred forty-five thousand, five hundred twenty-one".