21026316 has 12 divisors (see below), whose sum is σ = 49061432. Its totient is φ = 7008768.

The previous prime is 21026303. The next prime is 21026333. The reversal of 21026316 is 61362012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21026292 and 21026301.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 876085 + ... + 876108.

Almost surely, 2^21026316 is an apocalyptic number.

It is an amenable number.

21026316 is an abundant number, since it is smaller than the sum of its proper divisors (28035116).

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

21026316 is a wasteful number, since it uses less digits than its factorization.

21026316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1752200 (or 1752198 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21026316 is about 4585.4461069780. The cubic root of 21026316 is about 276.0076137366.

Adding to 21026316 its reverse (61362012), we get a palindrome (82388328).

The spelling of 21026316 in words is "twenty-one million, twenty-six thousand, three hundred sixteen".