1221252153 has 24 divisors (see below), whose sum is σ = 1800262464. Its totient is φ = 735836640.

The previous prime is 1221252143. The next prime is 1221252209. The reversal of 1221252153 is 3512521221.

It is not a de Polignac number, because 1221252153 - 2⁸ = 1221251897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221252143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53076 + ... + 72522.

It is an arithmetic number, because the mean of its divisors is an integer number (75010936).

Almost surely, 2^1221252153 is an apocalyptic number.

It is an amenable number.

1221252153 is a deficient number, since it is larger than the sum of its proper divisors (579010311).

1221252153 is a wasteful number, since it uses less digits than its factorization.

1221252153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19645 (or 19634 counting only the distinct ones).

The product of its digits is 1200, while the sum is 24.

The square root of 1221252153 is about 34946.4183143280. The cubic root of 1221252153 is about 1068.8951687353.

Adding to 1221252153 its reverse (3512521221), we get a palindrome (4733773374).

The spelling of 1221252153 in words is "one billion, two hundred twenty-one million, two hundred fifty-two thousand, one hundred fifty-three".