21818160 has 400 divisors, whose sum is σ = 95785536. Its totient is φ = 4478976.

The previous prime is 21818149. The next prime is 21818171. The reversal of 21818160 is 6181812.

It is an interprime number because it is at equal distance from previous prime (21818149) and next prime (21818171).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 589662 + ... + 589698.

Almost surely, 2^21818160 is an apocalyptic number.

21818160 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 21818160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47892768).

21818160 is an abundant number, since it is smaller than the sum of its proper divisors (73967376).

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

21818160 is a wasteful number, since it uses less digits than its factorization.

21818160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 21818160 is about 4670.9913294717. The cubic root of 21818160 is about 279.4297919649.

Adding to 21818160 its reverse (6181812), we get a palindrome (27999972).

The spelling of 21818160 in words is "twenty-one million, eight hundred eighteen thousand, one hundred sixty".