20121231384 has 80 divisors (see below), whose sum is σ = 56400268320. Its totient is φ = 6702056640.

The previous prime is 20121231371. The next prime is 20121231409. The reversal of 20121231384 is 48313212102.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 911194 + ... + 933014.

It is an arithmetic number, because the mean of its divisors is an integer number (705003354).

Almost surely, 2^20121231384 is an apocalyptic number.

20121231384 is a gapful number since it is divisible by the number (24) 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 20121231384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28200134160).

20121231384 is an abundant number, since it is smaller than the sum of its proper divisors (36279036936).

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

20121231384 is a wasteful number, since it uses less digits than its factorization.

20121231384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23262 (or 23249 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 20121231384 its reverse (48313212102), we get a palindrome (68434443486).

The spelling of 20121231384 in words is "twenty billion, one hundred twenty-one million, two hundred thirty-one thousand, three hundred eighty-four".