2621645 has 16 divisors (see below), whose sum is σ = 3456432. Its totient is φ = 1896960.

The previous prime is 2621617. The next prime is 2621669. The reversal of 2621645 is 5461262.

It can be written as a sum of positive squares in 8 ways, for example, as 644809 + 1976836 = 803^2 + 1406^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2621645 is a prime.

It is a super-3 number, since 3×2621645³ = 54055875263423733375, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3065 + ... + 3825.

It is an arithmetic number, because the mean of its divisors is an integer number (216027).

2^2621645 is an apocalyptic number.

It is an amenable number.

2621645 is a deficient number, since it is larger than the sum of its proper divisors (834787).

2621645 is a wasteful number, since it uses less digits than its factorization.

2621645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832.

The product of its digits is 2880, while the sum is 26.

The square root of 2621645 is about 1619.1494680850. The cubic root of 2621645 is about 137.8874142994.

The spelling of 2621645 in words is "two million, six hundred twenty-one thousand, six hundred forty-five".