21350 has 24 divisors (see below), whose sum is σ = 46128. Its totient is φ = 7200.

The previous prime is 21347. The next prime is 21377. The reversal of 21350 is 5312.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a zygodrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 320 + ... + 380.

It is an arithmetic number, because the mean of its divisors is an integer number (1922).

2²¹³⁵⁰ is an apocalyptic number.

21350 is an abundant number, since it is smaller than the sum of its proper divisors (24778).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23064).

21350 is a wasteful number, since it uses less digits than its factorization.

21350 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 21350 is about 146.1163919620. The cubic root of 21350 is about 27.7416716073.

Adding to 21350 its reverse (5312), we get a palindrome (26662).

The spelling of 21350 in words is "twenty-one thousand, three hundred fifty".