21910938 has 24 divisors (see below), whose sum is σ = 50977152. Its totient is φ = 6260184.

The previous prime is 21910937. The next prime is 21910957. The reversal of 21910938 is 83901912.

It is a junction number, because it is equal to n+sod(n) for n = 21910899 and 21910908.

It is not an unprimeable number, because it can be changed into a prime (21910937) 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 11 ways as a sum of consecutive naturals, for example, 36970 + ... + 37557.

It is an arithmetic number, because the mean of its divisors is an integer number (2124048).

Almost surely, 2^21910938 is an apocalyptic number.

21910938 is an abundant number, since it is smaller than the sum of its proper divisors (29066214).

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

21910938 is a wasteful number, since it uses less digits than its factorization.

21910938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74546 (or 74539 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 21910938 is about 4680.9120906080. The cubic root of 21910938 is about 279.8253076986.

The spelling of 21910938 in words is "twenty-one million, nine hundred ten thousand, nine hundred thirty-eight".