1231021220 has 48 divisors (see below), whose sum is σ = 3037099968. Its totient is φ = 413208960.

The previous prime is 1231021201. The next prime is 1231021237. The reversal of 1231021220 is 221201321.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1231021195 and 1231021204.

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, 212354 + ... + 218073.

It is an arithmetic number, because the mean of its divisors is an integer number (63272916).

Almost surely, 2^1231021220 is an apocalyptic number.

1231021220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231021220 is an abundant number, since it is smaller than the sum of its proper divisors (1806078748).

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

1231021220 is a wasteful number, since it uses less digits than its factorization.

1231021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430460 (or 430458 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 1231021220 is about 35085.9119875770. The cubic root of 1231021220 is about 1071.7377126652.

Adding to 1231021220 its reverse (221201321), we get a palindrome (1452222541).

The spelling of 1231021220 in words is "one billion, two hundred thirty-one million, twenty-one thousand, two hundred twenty".