20131220123340 has 96 divisors (see below), whose sum is σ = 59760358822080. Its totient is φ = 5046005047296.

The previous prime is 20131220123321. The next prime is 20131220123341. The reversal of 20131220123340 is 4332102213102.

It is a self number, because there is not a number n which added to its sum of digits gives 20131220123340.

It is not an unprimeable number, because it can be changed into a prime (20131220123341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11977705 + ... + 13554624.

It is an arithmetic number, because the mean of its divisors is an integer number (622503737730).

Almost surely, 2^{20131220123340} is an apocalyptic number.

20131220123340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20131220123340 is an abundant number, since it is smaller than the sum of its proper divisors (39629138698740).

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

20131220123340 is a wasteful number, since it uses less digits than its factorization.

20131220123340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25533131 (or 25533129 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 20131220123340 its reverse (4332102213102), we get a palindrome (24463322336442).

The spelling of 20131220123340 in words is "twenty trillion, one hundred thirty-one billion, two hundred twenty million, one hundred twenty-three thousand, three hundred forty".