1231322220 has 72 divisors (see below), whose sum is σ = 3741401664. Its totient is φ = 327790848.

The previous prime is 1231322219. The next prime is 1231322231. The reversal of 1231322220 is 222231321.

1231322220 is a `hidden beast` number, since 123 + 1 + 322 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1231322193 and 1231322202.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105517 + ... + 116603.

It is an arithmetic number, because the mean of its divisors is an integer number (51963912).

Almost surely, 2^1231322220 is an apocalyptic number.

1231322220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231322220 is an abundant number, since it is smaller than the sum of its proper divisors (2510079444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231322220 is a wasteful number, since it uses less digits than its factorization.

1231322220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11719 (or 11714 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 1231322220 is about 35090.2011963454. The cubic root of 1231322220 is about 1071.8250566138.

Adding to 1231322220 its reverse (222231321), we get a palindrome (1453553541).

The spelling of 1231322220 in words is "one billion, two hundred thirty-one million, three hundred twenty-two thousand, two hundred twenty".