21911938 has 8 divisors (see below), whose sum is σ = 32940288. Its totient is φ = 10931844.

The previous prime is 21911909. The next prime is 21911957. The reversal of 21911938 is 83911912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10906 + ... + 12757.

It is an arithmetic number, because the mean of its divisors is an integer number (4117536).

Almost surely, 2^21911938 is an apocalyptic number.

21911938 is a deficient number, since it is larger than the sum of its proper divisors (11028350).

21911938 is a wasteful number, since it uses less digits than its factorization.

21911938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24128.

The product of its digits is 3888, while the sum is 34.

The square root of 21911938 is about 4681.0189061784. The cubic root of 21911938 is about 279.8295646448.

The spelling of 21911938 in words is "twenty-one million, nine hundred eleven thousand, nine hundred thirty-eight".