1231021011220 has 768 divisors, whose sum is σ = 3793779763200. Its totient is φ = 329475686400.

The previous prime is 1231021011211. The next prime is 1231021011251. The reversal of 1231021011220 is 221101201321.

It is a super-2 number, since 2×1231021011220² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1231021011194 and 1231021011203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 1617635640 + ... + 1617636400.

It is an arithmetic number, because the mean of its divisors is an integer number (4939817400).

Almost surely, 2^{1231021011220} is an apocalyptic number.

1231021011220 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 1231021011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896889881600).

1231021011220 is an abundant number, since it is smaller than the sum of its proper divisors (2562758751980).

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

1231021011220 is a wasteful number, since it uses less digits than its factorization.

1231021011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 929 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 1231021011220 its reverse (221101201321), we get a palindrome (1452122212541).

The spelling of 1231021011220 in words is "one trillion, two hundred thirty-one billion, twenty-one million, eleven thousand, two hundred twenty".