21453331111 has 4 divisors (see below), whose sum is σ = 21952245832. Its totient is φ = 20954416392.

The previous prime is 21453331069. The next prime is 21453331147. The reversal of 21453331111 is 11113335412.

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 21453331111 - 2¹⁷ = 21453200039 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 (21453331511) 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, 249457296 + ... + 249457381.

It is an arithmetic number, because the mean of its divisors is an integer number (5488061458).

Almost surely, 2^21453331111 is an apocalyptic number.

21453331111 is a deficient number, since it is larger than the sum of its proper divisors (498914721).

21453331111 is an equidigital number, since it uses as much as digits as its factorization.

21453331111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498914720.

The product of its digits is 1080, while the sum is 25.

Adding to 21453331111 its reverse (11113335412), we get a palindrome (32566666523).

The spelling of 21453331111 in words is "twenty-one billion, four hundred fifty-three million, three hundred thirty-one thousand, one hundred eleven".