1231132221 has 12 divisors (see below), whose sum is σ = 1939966080. Its totient is φ = 746140680.

The previous prime is 1231132211. The next prime is 1231132223. The reversal of 1231132221 is 1222311321.

1231132221 is a `hidden beast` number, since 12 + 311 + 322 + 21 = 666.

It is not a de Polignac number, because 1231132221 - 2¹⁰ = 1231131197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1231132194 and 1231132203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231132223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6217741 + ... + 6217938.

It is an arithmetic number, because the mean of its divisors is an integer number (161663840).

Almost surely, 2^1231132221 is an apocalyptic number.

1231132221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231132221 is a deficient number, since it is larger than the sum of its proper divisors (708833859).

1231132221 is a wasteful number, since it uses less digits than its factorization.

1231132221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12435696 (or 12435693 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1231132221 is about 35087.4937976482. The cubic root of 1231132221 is about 1071.7699245070.

Adding to 1231132221 its reverse (1222311321), we get a palindrome (2453443542).

Subtracting from 1231132221 its reverse (1222311321), we obtain a square (8820900 = 2970²).

The spelling of 1231132221 in words is "one billion, two hundred thirty-one million, one hundred thirty-two thousand, two hundred twenty-one".