1231021133 has 4 divisors (see below), whose sum is σ = 1257213120. Its totient is φ = 1204829148.

The previous prime is 1231021123. The next prime is 1231021139. The reversal of 1231021133 is 3311201321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231021133 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 (1231021139) 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 3 ways as a sum of consecutive naturals, for example, 13095923 + ... + 13096016.

It is an arithmetic number, because the mean of its divisors is an integer number (314303280).

Almost surely, 2^1231021133 is an apocalyptic number.

It is an amenable number.

1231021133 is a deficient number, since it is larger than the sum of its proper divisors (26191987).

1231021133 is an equidigital number, since it uses as much as digits as its factorization.

1231021133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26191986.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1231021133 is about 35085.9107477631. The cubic root of 1231021133 is about 1071.7376874176.

Adding to 1231021133 its reverse (3311201321), we get a palindrome (4542222454).

The spelling of 1231021133 in words is "one billion, two hundred thirty-one million, twenty-one thousand, one hundred thirty-three".