2220645 has 16 divisors (see below), whose sum is σ = 4060800. Its totient is φ = 1015104.

The previous prime is 2220643. The next prime is 2220653. The reversal of 2220645 is 5460222.

It is not a de Polignac number, because 2220645 - 2¹ = 2220643 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2220643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10470 + ... + 10679.

It is an arithmetic number, because the mean of its divisors is an integer number (253800).

2^2220645 is an apocalyptic number.

It is an amenable number.

2220645 is a deficient number, since it is larger than the sum of its proper divisors (1840155).

2220645 is a wasteful number, since it uses less digits than its factorization.

2220645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21164.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 2220645 is about 1490.1828746835. The cubic root of 2220645 is about 130.4647076508.

Adding to 2220645 its reverse (5460222), we get a palindrome (7680867).

The spelling of 2220645 in words is "two million, two hundred twenty thousand, six hundred forty-five".