21402221111 has 4 divisors (see below), whose sum is σ = 22661175312. Its totient is φ = 20143266912.

The previous prime is 21402221107. The next prime is 21402221117. The reversal of 21402221111 is 11112220412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21402221111 - 2² = 21402221107 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 1258954183 = 21402221111 / (2 + 1 + 4 + 0 + 2 + 2 + 2 + 1 + 1 + 1 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21402221111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402221117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629477075 + ... + 629477108.

It is an arithmetic number, because the mean of its divisors is an integer number (5665293828).

Almost surely, 2^21402221111 is an apocalyptic number.

21402221111 is a deficient number, since it is larger than the sum of its proper divisors (1258954201).

21402221111 is a wasteful number, since it uses less digits than its factorization.

21402221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258954200.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21402221111 its reverse (11112220412), we get a palindrome (32514441523).

The spelling of 21402221111 in words is "twenty-one billion, four hundred two million, two hundred twenty-one thousand, one hundred eleven".