21203021111 has 16 divisors (see below), whose sum is σ = 22029840000. Its totient is φ = 20382796896.

The previous prime is 21203021107. The next prime is 21203021141. The reversal of 21203021111 is 11112030212.

It is a cyclic number.

It is not a de Polignac number, because 21203021111 - 2² = 21203021107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203021141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7520060 + ... + 7522878.

It is an arithmetic number, because the mean of its divisors is an integer number (1376865000).

Almost surely, 2^21203021111 is an apocalyptic number.

21203021111 is a deficient number, since it is larger than the sum of its proper divisors (826818889).

21203021111 is a wasteful number, since it uses less digits than its factorization.

21203021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21203021111 its reverse (11112030212), we get a palindrome (32315051323).

The spelling of 21203021111 in words is "twenty-one billion, two hundred three million, twenty-one thousand, one hundred eleven".