21001111002 has 16 divisors (see below), whose sum is σ = 46669135680. Its totient is φ = 7000370316.

The previous prime is 21001110967. The next prime is 21001111063. The reversal of 21001111002 is 20011110012.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194454678 + ... + 194454785.

It is an arithmetic number, because the mean of its divisors is an integer number (2916820980).

Almost surely, 2^21001111002 is an apocalyptic number.

21001111002 is an abundant number, since it is smaller than the sum of its proper divisors (25668024678).

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

21001111002 is a wasteful number, since it uses less digits than its factorization.

21001111002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388909474 (or 388909468 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21001111002 its reverse (20011110012), we get a palindrome (41012221014).

The spelling of 21001111002 in words is "twenty-one billion, one million, one hundred eleven thousand, two".