21911838 has 16 divisors (see below), whose sum is σ = 47194896. Its totient is φ = 6742080.

The previous prime is 21911837. The next prime is 21911839. The reversal of 21911838 is 83811912.

It is an interprime number because it is at equal distance from previous prime (21911837) and next prime (21911839).

It is a junction number, because it is equal to n+sod(n) for n = 21911799 and 21911808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21911837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140383 + ... + 140538.

It is an arithmetic number, because the mean of its divisors is an integer number (2949681).

Almost surely, 2^21911838 is an apocalyptic number.

21911838 is an abundant number, since it is smaller than the sum of its proper divisors (25283058).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21911838 is a wasteful number, since it uses less digits than its factorization.

21911838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280939.

The product of its digits is 3456, while the sum is 33.

The square root of 21911838 is about 4681.0082247311. The cubic root of 21911838 is about 279.8291389560.

The spelling of 21911838 in words is "twenty-one million, nine hundred eleven thousand, eight hundred thirty-eight".