1221131253 has 8 divisors (see below), whose sum is σ = 1628336416. Its totient is φ = 814006800.

The previous prime is 1221131189. The next prime is 1221131321. The reversal of 1221131253 is 3521311221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221131253 - 2⁶ = 1221131189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221131453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49863 + ... + 70203.

It is an arithmetic number, because the mean of its divisors is an integer number (203542052).

Almost surely, 2^1221131253 is an apocalyptic number.

It is an amenable number.

1221131253 is a deficient number, since it is larger than the sum of its proper divisors (407205163).

1221131253 is a wasteful number, since it uses less digits than its factorization.

1221131253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40355.

The product of its digits is 360, while the sum is 21.

The square root of 1221131253 is about 34944.6884805116. The cubic root of 1221131253 is about 1068.8598951870.

Adding to 1221131253 its reverse (3521311221), we get a palindrome (4742442474).

The spelling of 1221131253 in words is "one billion, two hundred twenty-one million, one hundred thirty-one thousand, two hundred fifty-three".