12131221020 has 24 divisors (see below), whose sum is σ = 33967419024. Its totient is φ = 3234992256.

The previous prime is 12131221019. The next prime is 12131221031. The reversal of 12131221020 is 2012213121.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 101093449 + ... + 101093568.

It is an arithmetic number, because the mean of its divisors is an integer number (1415309126).

Almost surely, 2^12131221020 is an apocalyptic number.

12131221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12131221020 is an abundant number, since it is smaller than the sum of its proper divisors (21836198004).

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

12131221020 is a wasteful number, since it uses less digits than its factorization.

12131221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202187029 (or 202187027 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 12131221020 its reverse (2012213121), we get a palindrome (14143434141).

The spelling of 12131221020 in words is "twelve billion, one hundred thirty-one million, two hundred twenty-one thousand, twenty".