21387382 has 16 divisors (see below), whose sum is σ = 32817600. Its totient is φ = 10450440.

The previous prime is 21387361. The next prime is 21387389. The reversal of 21387382 is 28378312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24469 + ... + 25327.

It is an arithmetic number, because the mean of its divisors is an integer number (2051100).

Almost surely, 2^21387382 is an apocalyptic number.

21387382 is a deficient number, since it is larger than the sum of its proper divisors (11430218).

21387382 is a wasteful number, since it uses less digits than its factorization.

21387382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131.

The product of its digits is 16128, while the sum is 34.

The square root of 21387382 is about 4624.6493921161. The cubic root of 21387382 is about 277.5785325442.

The spelling of 21387382 in words is "twenty-one million, three hundred eighty-seven thousand, three hundred eighty-two".