1231205020 has 24 divisors (see below), whose sum is σ = 2586949344. Its totient is φ = 492211776.

The previous prime is 1231205009. The next prime is 1231205033. The reversal of 1231205020 is 205021321.

It is a junction number, because it is equal to n+sod(n) for n = 1231204985 and 1231205003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22737 + ... + 54583.

It is an arithmetic number, because the mean of its divisors is an integer number (107789556).

Almost surely, 2^1231205020 is an apocalyptic number.

1231205020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231205020 is an abundant number, since it is smaller than the sum of its proper divisors (1355744324).

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

1231205020 is a wasteful number, since it uses less digits than its factorization.

1231205020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33789 (or 33787 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1231205020 is about 35088.5311747300. The cubic root of 1231205020 is about 1071.7910493003.

Adding to 1231205020 its reverse (205021321), we get a palindrome (1436226341).

The spelling of 1231205020 in words is "one billion, two hundred thirty-one million, two hundred five thousand, twenty".