21905043111 has 20 divisors (see below), whose sum is σ = 37396970512. Its totient is φ = 12517167168.

The previous prime is 21905043079. The next prime is 21905043137. The reversal of 21905043111 is 11134050912.

It is a happy number.

21905043111 is a `hidden beast` number, since 219 + 0 + 5 + 0 + 431 + 11 = 666.

It is not a de Polignac number, because 21905043111 - 2⁵ = 21905043079 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905043151) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 19316050 + ... + 19317183.

Almost surely, 2^21905043111 is an apocalyptic number.

21905043111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21905043111 is a deficient number, since it is larger than the sum of its proper divisors (15491927401).

21905043111 is an equidigital number, since it uses as much as digits as its factorization.

21905043111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38633252 (or 38633243 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The spelling of 21905043111 in words is "twenty-one billion, nine hundred five million, forty-three thousand, one hundred eleven".