21850724 has 12 divisors (see below), whose sum is σ = 43701504. Its totient is φ = 9364584.

The previous prime is 21850721. The next prime is 21850733. The reversal of 21850724 is 42705812.

21850724 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21850721) 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, 390164 + ... + 390219.

It is an arithmetic number, because the mean of its divisors is an integer number (3641792).

Almost surely, 2^21850724 is an apocalyptic number.

It is an amenable number.

21850724 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21850724 is a wasteful number, since it uses less digits than its factorization.

21850724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780394 (or 780392 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 21850724 is about 4674.4757994881. The cubic root of 21850724 is about 279.5687408728.

The spelling of 21850724 in words is "twenty-one million, eight hundred fifty thousand, seven hundred twenty-four".