1231051231 has 4 divisors (see below), whose sum is σ = 1231303752. Its totient is φ = 1230798712.

The previous prime is 1231051177. The next prime is 1231051279. The reversal of 1231051231 is 1321501321.

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-1231051231 is a prime.

It is a super-2 number, since 2×1231051231² = 3030974266693230722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231051199 and 1231051208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231051631) 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, 118801 + ... + 128746.

It is an arithmetic number, because the mean of its divisors is an integer number (307825938).

Almost surely, 2^1231051231 is an apocalyptic number.

1231051231 is a deficient number, since it is larger than the sum of its proper divisors (252521).

1231051231 is an equidigital number, since it uses as much as digits as its factorization.

1231051231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252520.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1231051231 is about 35086.3396637495. The cubic root of 1231051231 is about 1071.7464218731.

Adding to 1231051231 its reverse (1321501321), we get a palindrome (2552552552).

The spelling of 1231051231 in words is "one billion, two hundred thirty-one million, fifty-one thousand, two hundred thirty-one".