1220445 has 24 divisors (see below), whose sum is σ = 2175576. Its totient is φ = 632448.

The previous prime is 1220437. The next prime is 1220489. The reversal of 1220445 is 5440221.

1220445 is a `hidden beast` number, since 1 + 220 + 445 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 710649 + 509796 = 843^2 + 714^2 .

It is not a de Polignac number, because 1220445 - 2³ = 1220437 is a prime.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1299 + ... + 2031.

It is an arithmetic number, because the mean of its divisors is an integer number (90649).

2^1220445 is an apocalyptic number.

1220445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1220445 is a deficient number, since it is larger than the sum of its proper divisors (955131).

1220445 is a wasteful number, since it uses less digits than its factorization.

1220445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 1220445 is about 1104.7375253878. The cubic root of 1220445 is about 106.8659631222.

Adding to 1220445 its reverse (5440221), we get a palindrome (6660666).

The spelling of 1220445 in words is "one million, two hundred twenty thousand, four hundred forty-five".