21875742 has 24 divisors (see below), whose sum is σ = 54168816. Its totient is φ = 6250176.

The previous prime is 21875713. The next prime is 21875747. The reversal of 21875742 is 24757812.

21875742 is a `hidden beast` number, since 2 + 1 + 87 + 574 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21875697 and 21875706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21875747) 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, 86683 + ... + 86934.

It is an arithmetic number, because the mean of its divisors is an integer number (2257034).

Almost surely, 2^21875742 is an apocalyptic number.

21875742 is an abundant number, since it is smaller than the sum of its proper divisors (32293074).

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

21875742 is a wasteful number, since it uses less digits than its factorization.

21875742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173632 (or 173629 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 21875742 is about 4677.1510559314. The cubic root of 21875742 is about 279.6753976453.

The spelling of 21875742 in words is "twenty-one million, eight hundred seventy-five thousand, seven hundred forty-two".