21350289 has 16 divisors (see below), whose sum is σ = 29689344. Its totient is φ = 13632000.

The previous prime is 21350213. The next prime is 21350291. The reversal of 21350289 is 98205312.

It is a happy number.

It is not a de Polignac number, because 21350289 - 2¹⁵ = 21317521 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21351289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8257 + ... + 10529.

It is an arithmetic number, because the mean of its divisors is an integer number (1855584).

Almost surely, 2^21350289 is an apocalyptic number.

It is an amenable number.

21350289 is a deficient number, since it is larger than the sum of its proper divisors (8339055).

21350289 is a wasteful number, since it uses less digits than its factorization.

21350289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2408.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21350289 is about 4620.6372937074. The cubic root of 21350289 is about 277.4179677988.

The spelling of 21350289 in words is "twenty-one million, three hundred fifty thousand, two hundred eighty-nine".