21930111 has 12 divisors (see below), whose sum is σ = 36202192. Its totient is φ = 12531456.

The previous prime is 21930107. The next prime is 21930131. The reversal of 21930111 is 11103912.

It is not a de Polignac number, because 21930111 - 2² = 21930107 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 (21930101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 173986 + ... + 174111.

Almost surely, 2^21930111 is an apocalyptic number.

21930111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21930111 is a deficient number, since it is larger than the sum of its proper divisors (14272081).

21930111 is a wasteful number, since it uses less digits than its factorization.

21930111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348110 (or 348107 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 18.

The square root of 21930111 is about 4682.9596410817. The cubic root of 21930111 is about 279.9069035739.

The spelling of 21930111 in words is "twenty-one million, nine hundred thirty thousand, one hundred eleven".