21236485 has 16 divisors (see below), whose sum is σ = 27092016. Its totient is φ = 15925248.

The previous prime is 21236477. The next prime is 21236491. The reversal of 21236485 is 58463212.

It can be written as a sum of positive squares in 8 ways, for example, as 887364 + 20349121 = 942^2 + 4511^2 .

It is a 8-Lehmer number, since φ(21236485) divides (21236485-1)⁸.

It is a cyclic number.

It is not a de Polignac number, because 21236485 - 2³ = 21236477 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36517 + ... + 37093.

It is an arithmetic number, because the mean of its divisors is an integer number (1693251).

Almost surely, 2^21236485 is an apocalyptic number.

It is an amenable number.

21236485 is a deficient number, since it is larger than the sum of its proper divisors (5855531).

21236485 is a wasteful number, since it uses less digits than its factorization.

21236485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032.

The product of its digits is 11520, while the sum is 31.

The square root of 21236485 is about 4608.3060879243. The cubic root of 21236485 is about 276.9241800071.

Adding to 21236485 its reverse (58463212), we get a palindrome (79699697).

The spelling of 21236485 in words is "twenty-one million, two hundred thirty-six thousand, four hundred eighty-five".