21010020012 has 18 divisors (see below), whose sum is σ = 53108661788. Its totient is φ = 7003339992.

The previous prime is 21010020007. The next prime is 21010020047. The reversal of 21010020012 is 21002001012.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21010019976 and 21010020003.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 291805798 + ... + 291805869.

Almost surely, 2^21010020012 is an apocalyptic number.

It is an amenable number.

21010020012 is an abundant number, since it is smaller than the sum of its proper divisors (32098641776).

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

21010020012 is a wasteful number, since it uses less digits than its factorization.

21010020012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583611677 (or 583611672 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21010020012 its reverse (21002001012), we get a palindrome (42012021024).

The spelling of 21010020012 in words is "twenty-one billion, ten million, twenty thousand, twelve".