21421585111 has 2 divisors, whose sum is σ = 21421585112. Its totient is φ = 21421585110.

The previous prime is 21421585109. The next prime is 21421585177. The reversal of 21421585111 is 11158512412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21421585111 - 2¹ = 21421585109 is a prime.

Together with 21421585109, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421582111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710792555 + 10710792556.

It is an arithmetic number, because the mean of its divisors is an integer number (10710792556).

Almost surely, 2^21421585111 is an apocalyptic number.

21421585111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421585111 is an equidigital number, since it uses as much as digits as its factorization.

21421585111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3200, while the sum is 31.

The spelling of 21421585111 in words is "twenty-one billion, four hundred twenty-one million, five hundred eighty-five thousand, one hundred eleven".