21738360 has 96 divisors (see below), whose sum is σ = 75882960. Its totient is φ = 4967424.

The previous prime is 21738329. The next prime is 21738361. The reversal of 21738360 is 6383712.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738361) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4032 + ... + 7728.

Almost surely, 2^21738360 is an apocalyptic number.

21738360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21738360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37941480).

21738360 is an abundant number, since it is smaller than the sum of its proper divisors (54144600).

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

21738360 is a wasteful number, since it uses less digits than its factorization.

21738360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3725 (or 3714 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 21738360 is about 4662.4414205435. The cubic root of 21738360 is about 279.0887039540.

The spelling of 21738360 in words is "twenty-one million, seven hundred thirty-eight thousand, three hundred sixty".