21237384 has 48 divisors (see below), whose sum is σ = 61765200. Its totient is φ = 6067488.

The previous prime is 21237353. The next prime is 21237389. The reversal of 21237384 is 48373212.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21237389) 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, 7854 + ... + 10205.

It is an arithmetic number, because the mean of its divisors is an integer number (1286775).

Almost surely, 2^21237384 is an apocalyptic number.

21237384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21237384 is an abundant number, since it is smaller than the sum of its proper divisors (40527816).

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

21237384 is a wasteful number, since it uses less digits than its factorization.

21237384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18082 (or 18071 counting only the distinct ones).

The product of its digits is 8064, while the sum is 30.

The square root of 21237384 is about 4608.4036281558. The cubic root of 21237384 is about 276.9280876111.

The spelling of 21237384 in words is "twenty-one million, two hundred thirty-seven thousand, three hundred eighty-four".