21824380 has 12 divisors (see below), whose sum is σ = 45831240. Its totient is φ = 8729744.

The previous prime is 21824371. The next prime is 21824381. The reversal of 21824380 is 8342812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21824381) 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, 545590 + ... + 545629.

It is an arithmetic number, because the mean of its divisors is an integer number (3819270).

Almost surely, 2^21824380 is an apocalyptic number.

21824380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21824380 is an abundant number, since it is smaller than the sum of its proper divisors (24006860).

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

21824380 is a wasteful number, since it uses less digits than its factorization.

21824380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091228 (or 1091226 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 21824380 is about 4671.6570935804. The cubic root of 21824380 is about 279.4563430607.

The spelling of 21824380 in words is "twenty-one million, eight hundred twenty-four thousand, three hundred eighty".