1220121144 has 160 divisors (see below), whose sum is σ = 3947842800. Its totient is φ = 347950080.

The previous prime is 1220121137. The next prime is 1220121151. The reversal of 1220121144 is 4411210221.

It is an interprime number because it is at equal distance from previous prime (1220121137) and next prime (1220121151).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 39 ways as a sum of consecutive naturals, for example, 116142 + ... + 126210.

Almost surely, 2^1220121144 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 1220121144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1973921400).

1220121144 is an abundant number, since it is smaller than the sum of its proper divisors (2727721656).

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

1220121144 is a wasteful number, since it uses less digits than its factorization.

1220121144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10115 (or 10102 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1220121144 is about 34930.2325214133. The cubic root of 1220121144 is about 1068.5650967285.

Adding to 1220121144 its reverse (4411210221), we get a palindrome (5631331365).

The spelling of 1220121144 in words is "one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred forty-four".