21975842 has 8 divisors (see below), whose sum is σ = 37672896. Its totient is φ = 9418212.

The previous prime is 21975841. The next prime is 21975851. The reversal of 21975842 is 24857912.

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

It is a junction number, because it is equal to n+sod(n) for n = 21975796 and 21975805.

It is not an unprimeable number, because it can be changed into a prime (21975841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 784838 + ... + 784865.

It is an arithmetic number, because the mean of its divisors is an integer number (4709112).

Almost surely, 2^21975842 is an apocalyptic number.

21975842 is a deficient number, since it is larger than the sum of its proper divisors (15697054).

21975842 is a wasteful number, since it uses less digits than its factorization.

21975842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1569712.

The product of its digits is 40320, while the sum is 38.

The square root of 21975842 is about 4687.8398010171. The cubic root of 21975842 is about 280.1013323709.

The spelling of 21975842 in words is "twenty-one million, nine hundred seventy-five thousand, eight hundred forty-two".