21873042 has 24 divisors (see below), whose sum is σ = 48921600. Its totient is φ = 7055640.

The previous prime is 21873037. The next prime is 21873043. The reversal of 21873042 is 24037812.

It is a junction number, because it is equal to n+sod(n) for n = 21872997 and 21873015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21873043) 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 11 ways as a sum of consecutive naturals, for example, 19042 + ... + 20157.

It is an arithmetic number, because the mean of its divisors is an integer number (2038400).

Almost surely, 2^21873042 is an apocalyptic number.

21873042 is an abundant number, since it is smaller than the sum of its proper divisors (27048558).

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

21873042 is a wasteful number, since it uses less digits than its factorization.

21873042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39238 (or 39235 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21873042 is about 4676.8624097786. The cubic root of 21873042 is about 279.6638909173.

The spelling of 21873042 in words is "twenty-one million, eight hundred seventy-three thousand, forty-two".