21011111002 has 64 divisors (see below), whose sum is σ = 39456668160. Its totient is φ = 8186112000.

The previous prime is 21011110999. The next prime is 21011111003. The reversal of 21011111002 is 20011111012.

It is a self number, because there is not a number n which added to its sum of digits gives 21011111002.

It is not an unprimeable number, because it can be changed into a prime (21011111003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 974899 + ... + 996217.

It is an arithmetic number, because the mean of its divisors is an integer number (616510440).

Almost surely, 2^21011111002 is an apocalyptic number.

21011111002 is a deficient number, since it is larger than the sum of its proper divisors (18445557158).

21011111002 is a wasteful number, since it uses less digits than its factorization.

21011111002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21487.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21011111002 its sum of digits (10), we get a palindrome (21011111012).

Adding to 21011111002 its reverse (20011111012), we get a palindrome (41022222014).

The spelling of 21011111002 in words is "twenty-one billion, eleven million, one hundred eleven thousand, two".