20121231020 has 48 divisors (see below), whose sum is σ = 46745185536. Its totient is φ = 7213752000.

The previous prime is 20121230981. The next prime is 20121231023. The reversal of 20121231020 is 2013212102.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20121230986 and 20121231004.

It is not an unprimeable number, because it can be changed into a prime (20121231023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 628466 + ... + 659705.

It is an arithmetic number, because the mean of its divisors is an integer number (973858032).

Almost surely, 2^20121231020 is an apocalyptic number.

20121231020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121231020 is an abundant number, since it is smaller than the sum of its proper divisors (26623954516).

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

20121231020 is a wasteful number, since it uses less digits than its factorization.

20121231020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288262 (or 1288260 counting only the distinct ones).

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

Adding to 20121231020 its reverse (2013212102), we get a palindrome (22134443122).

It can be divided in two parts, 201212 and 31020, that added together give a palindrome (232232).

The spelling of 20121231020 in words is "twenty billion, one hundred twenty-one million, two hundred thirty-one thousand, twenty".