21235316 has 6 divisors (see below), whose sum is σ = 37161810. Its totient is φ = 10617656.

The previous prime is 21235297. The next prime is 21235343. The reversal of 21235316 is 61353212.

It can be written as a sum of positive squares in only one way, i.e., 15570916 + 5664400 = 3946^2 + 2380^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21235291 and 21235300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2654411 + ... + 2654418.

It is an arithmetic number, because the mean of its divisors is an integer number (6193635).

Almost surely, 2^21235316 is an apocalyptic number.

It is an amenable number.

21235316 is a deficient number, since it is larger than the sum of its proper divisors (15926494).

21235316 is a wasteful number, since it uses less digits than its factorization.

21235316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5308833 (or 5308831 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 21235316 is about 4608.1792499858. The cubic root of 21235316 is about 276.9190986529.

Adding to 21235316 its reverse (61353212), we get a palindrome (82588528).

The spelling of 21235316 in words is "twenty-one million, two hundred thirty-five thousand, three hundred sixteen".