1231353551 has 4 divisors (see below), whose sum is σ = 1231466400. Its totient is φ = 1231240704.

The previous prime is 1231353527. The next prime is 1231353559. The reversal of 1231353551 is 1553531321.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231353551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231353559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38066 + ... + 62543.

It is an arithmetic number, because the mean of its divisors is an integer number (307866600).

Almost surely, 2^1231353551 is an apocalyptic number.

1231353551 is a deficient number, since it is larger than the sum of its proper divisors (112849).

1231353551 is a wasteful number, since it uses less digits than its factorization.

1231353551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112848.

The product of its digits is 6750, while the sum is 29.

The square root of 1231353551 is about 35090.6476286774. The cubic root of 1231353551 is about 1071.8341474013.

Adding to 1231353551 its reverse (1553531321), we get a palindrome (2784884872).

The spelling of 1231353551 in words is "one billion, two hundred thirty-one million, three hundred fifty-three thousand, five hundred fifty-one".