21130020012 has 24 divisors (see below), whose sum is σ = 49588375536. Its totient is φ = 7002626368.

The previous prime is 21130019941. The next prime is 21130020013. The reversal of 21130020012 is 21002003112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21130020012.

It is not an unprimeable number, because it can be changed into a prime (21130020013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5087043 + ... + 5091194.

It is an arithmetic number, because the mean of its divisors is an integer number (2066182314).

Almost surely, 2^21130020012 is an apocalyptic number.

It is an amenable number.

21130020012 is an abundant number, since it is smaller than the sum of its proper divisors (28458355524).

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

21130020012 is a wasteful number, since it uses less digits than its factorization.

21130020012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10178417 (or 10178415 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21130020012 its reverse (21002003112), we get a palindrome (42132023124).

The spelling of 21130020012 in words is "twenty-one billion, one hundred thirty million, twenty thousand, twelve".