1221154452 has 36 divisors (see below), whose sum is σ = 3527780256. Its totient is φ = 348901200.

The previous prime is 1221154409. The next prime is 1221154483. The reversal of 1221154452 is 2544511221.

It is a happy number.

1221154452 is a `hidden beast` number, since 1 + 2 + 211 + 5 + 445 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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 11 ways as a sum of consecutive naturals, for example, 2422674 + ... + 2423177.

It is an arithmetic number, because the mean of its divisors is an integer number (97993896).

Almost surely, 2^1221154452 is an apocalyptic number.

1221154452 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221154452 is an abundant number, since it is smaller than the sum of its proper divisors (2306625804).

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

1221154452 is a wasteful number, since it uses less digits than its factorization.

1221154452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4845868 (or 4845863 counting only the distinct ones).

The product of its digits is 3200, while the sum is 27.

The square root of 1221154452 is about 34945.0204177934. The cubic root of 1221154452 is about 1068.8666638625.

Adding to 1221154452 its reverse (2544511221), we get a palindrome (3765665673).

The spelling of 1221154452 in words is "one billion, two hundred twenty-one million, one hundred fifty-four thousand, four hundred fifty-two".