1221122544 has 80 divisors (see below), whose sum is σ = 3301208352. Its totient is φ = 388537344.

The previous prime is 1221122543. The next prime is 1221122569. The reversal of 1221122544 is 4452211221.

It is a super-2 number, since 2×1221122544² = 2982280534930063872, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221122543) 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, 87642 + ... + 100614.

Almost surely, 2^1221122544 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 1221122544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1650604176).

1221122544 is an abundant number, since it is smaller than the sum of its proper divisors (2080085808).

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

1221122544 is a wasteful number, since it uses less digits than its factorization.

1221122544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13074 (or 13068 counting only the distinct ones).

The product of its digits is 1280, while the sum is 24.

The square root of 1221122544 is about 34944.5638690770. The cubic root of 1221122544 is about 1068.8573541762.

Adding to 1221122544 its reverse (4452211221), we get a palindrome (5673333765).

The spelling of 1221122544 in words is "one billion, two hundred twenty-one million, one hundred twenty-two thousand, five hundred forty-four".