21842572 has 24 divisors (see below), whose sum is σ = 39218256. Its totient is φ = 10640448.

The previous prime is 21842551. The next prime is 21842573. The reversal of 21842572 is 27524812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21842573) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 41503 + ... + 42025.

It is an arithmetic number, because the mean of its divisors is an integer number (1634094).

Almost surely, 2^21842572 is an apocalyptic number.

It is an amenable number.

21842572 is a deficient number, since it is larger than the sum of its proper divisors (17375684).

21842572 is a wasteful number, since it uses less digits than its factorization.

21842572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777 (or 775 counting only the distinct ones).

The product of its digits is 8960, while the sum is 31.

The square root of 21842572 is about 4673.6037487147. The cubic root of 21842572 is about 279.5339696702.

The spelling of 21842572 in words is "twenty-one million, eight hundred forty-two thousand, five hundred seventy-two".