1220155144 has 64 divisors (see below), whose sum is σ = 2634917040. Its totient is φ = 524697600.

The previous prime is 1220155141. The next prime is 1220155159. The reversal of 1220155144 is 4415510221.

It can be written as a sum of positive squares in 8 ways, for example, as 650760100 + 569395044 = 25510^2 + 23862^2 .

It is not an unprimeable number, because it can be changed into a prime (1220155141) 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, 175152 + ... + 181984.

Almost surely, 2^1220155144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220155144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1317458520).

1220155144 is an abundant number, since it is smaller than the sum of its proper divisors (1414761896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1220155144 is a wasteful number, since it uses less digits than its factorization.

1220155144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6970 (or 6966 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 1220155144 is about 34930.7192024441. The cubic root of 1220155144 is about 1068.5750222117.

Adding to 1220155144 its reverse (4415510221), we get a palindrome (5635665365).

The spelling of 1220155144 in words is "one billion, two hundred twenty million, one hundred fifty-five thousand, one hundred forty-four".