21231016 has 16 divisors (see below), whose sum is σ = 41181300. Its totient is φ = 10249344.

The previous prime is 21230969. The next prime is 21231029. The reversal of 21231016 is 61013212.

It can be written as a sum of positive squares in 2 ways, for example, as 19766916 + 1464100 = 4446^2 + 1210^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45525 + ... + 45988.

Almost surely, 2^21231016 is an apocalyptic number.

It is an amenable number.

21231016 is a deficient number, since it is larger than the sum of its proper divisors (19950284).

21231016 is a wasteful number, since it uses less digits than its factorization.

21231016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91548 (or 91544 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21231016 is about 4607.7126646526. The cubic root of 21231016 is about 276.9004060105.

Adding to 21231016 its reverse (61013212), we get a palindrome (82244228).

The spelling of 21231016 in words is "twenty-one million, two hundred thirty-one thousand, sixteen".