1231122220 has 48 divisors (see below), whose sum is σ = 2672587008. Its totient is φ = 475879680.

The previous prime is 1231122197. The next prime is 1231122247. The reversal of 1231122220 is 222211321.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1231122194 and 1231122203.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 751242 + ... + 752878.

It is an arithmetic number, because the mean of its divisors is an integer number (55678896).

Almost surely, 2^1231122220 is an apocalyptic number.

1231122220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231122220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1336293504).

1231122220 is an abundant number, since it is smaller than the sum of its proper divisors (1441464788).

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

1231122220 is a wasteful number, since it uses less digits than its factorization.

1231122220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2890 (or 2888 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1231122220 is about 35087.3512821928. The cubic root of 1231122220 is about 1071.7670223546.

Adding to 1231122220 its reverse (222211321), we get a palindrome (1453333541).

The spelling of 1231122220 in words is "one billion, two hundred thirty-one million, one hundred twenty-two thousand, two hundred twenty".