13121320020 has 48 divisors (see below), whose sum is σ = 36820166208. Its totient is φ = 3491354880.

The previous prime is 13121319989. The next prime is 13121320031. The reversal of 13121320020 is 2002312131.

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 15 ways as a sum of consecutive naturals, for example, 211846 + ... + 266685.

It is an arithmetic number, because the mean of its divisors is an integer number (767086796).

Almost surely, 2^13121320020 is an apocalyptic number.

13121320020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13121320020 is an abundant number, since it is smaller than the sum of its proper divisors (23698846188).

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

13121320020 is a wasteful number, since it uses less digits than its factorization.

13121320020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479000 (or 478998 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 13121320020 its reverse (2002312131), we get a palindrome (15123632151).

The spelling of 13121320020 in words is "thirteen billion, one hundred twenty-one million, three hundred twenty thousand, twenty".