21873450 has 24 divisors (see below), whose sum is σ = 54246528. Its totient is φ = 5832880.

The previous prime is 21873433. The next prime is 21873451. The reversal of 21873450 is 5437812.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21873451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72762 + ... + 73061.

It is an arithmetic number, because the mean of its divisors is an integer number (2260272).

Almost surely, 2^21873450 is an apocalyptic number.

21873450 is an abundant number, since it is smaller than the sum of its proper divisors (32373078).

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

21873450 is a wasteful number, since it uses less digits than its factorization.

21873450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145838 (or 145833 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21873450 is about 4676.9060285620. The cubic root of 21873450 is about 279.6656297725.

The spelling of 21873450 in words is "twenty-one million, eight hundred seventy-three thousand, four hundred fifty".