1220440555 has 4 divisors (see below), whose sum is σ = 1464528672. Its totient is φ = 976352440.

The previous prime is 1220440541. The next prime is 1220440579. The reversal of 1220440555 is 5550440221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5550440221 = 27067 ⋅205063.

It is not a de Polignac number, because 1220440555 - 2¹¹ = 1220438507 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122044051 + ... + 122044060.

It is an arithmetic number, because the mean of its divisors is an integer number (366132168).

Almost surely, 2^1220440555 is an apocalyptic number.

1220440555 is a deficient number, since it is larger than the sum of its proper divisors (244088117).

1220440555 is an equidigital number, since it uses as much as digits as its factorization.

1220440555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244088116.

The product of its (nonzero) digits is 8000, while the sum is 28.

The square root of 1220440555 is about 34934.8043503896. The cubic root of 1220440555 is about 1068.6583338272.

Adding to 1220440555 its reverse (5550440221), we get a palindrome (6770880776).

The spelling of 1220440555 in words is "one billion, two hundred twenty million, four hundred forty thousand, five hundred fifty-five".