1231511222 has 16 divisors (see below), whose sum is σ = 1861719552. Its totient is φ = 610955520.

The previous prime is 1231511213. The next prime is 1231511269. The reversal of 1231511222 is 2221151321.

It is a junction number, because it is equal to n+sod(n) for n = 1231511194 and 1231511203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146822 + ... + 154982.

It is an arithmetic number, because the mean of its divisors is an integer number (116357472).

Almost surely, 2^1231511222 is an apocalyptic number.

1231511222 is a deficient number, since it is larger than the sum of its proper divisors (630208330).

1231511222 is a wasteful number, since it uses less digits than its factorization.

1231511222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8743.

The product of its digits is 240, while the sum is 20.

The square root of 1231511222 is about 35092.8941810162. The cubic root of 1231511222 is about 1071.8798937940.

Adding to 1231511222 its reverse (2221151321), we get a palindrome (3452662543).

The spelling of 1231511222 in words is "one billion, two hundred thirty-one million, five hundred eleven thousand, two hundred twenty-two".