1231535553 has 8 divisors (see below), whose sum is σ = 1643008416. Its totient is φ = 820543200.

The previous prime is 1231535551. The next prime is 1231535587. The reversal of 1231535553 is 3555351321.

It is a happy number.

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

It is not a de Polignac number, because 1231535553 - 2¹ = 1231535551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231535551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 114103 + ... + 124428.

It is an arithmetic number, because the mean of its divisors is an integer number (205376052).

Almost surely, 2^1231535553 is an apocalyptic number.

It is an amenable number.

1231535553 is a deficient number, since it is larger than the sum of its proper divisors (411472863).

1231535553 is a wasteful number, since it uses less digits than its factorization.

1231535553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240255.

The product of its digits is 33750, while the sum is 33.

The square root of 1231535553 is about 35093.2408449262. The cubic root of 1231535553 is about 1071.8869528007.

Adding to 1231535553 its reverse (3555351321), we get a palindrome (4786886874).

The spelling of 1231535553 in words is "one billion, two hundred thirty-one million, five hundred thirty-five thousand, five hundred fifty-three".