21154424111 has 2 divisors, whose sum is σ = 21154424112. Its totient is φ = 21154424110.

The previous prime is 21154424101. The next prime is 21154424143. The reversal of 21154424111 is 11142445112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21154424111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21154424101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577212055 + 10577212056.

It is an arithmetic number, because the mean of its divisors is an integer number (10577212056).

Almost surely, 2^21154424111 is an apocalyptic number.

21154424111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154424111 is an equidigital number, since it uses as much as digits as its factorization.

21154424111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1280, while the sum is 26.

Adding to 21154424111 its reverse (11142445112), we get a palindrome (32296869223).

The spelling of 21154424111 in words is "twenty-one billion, one hundred fifty-four million, four hundred twenty-four thousand, one hundred eleven".