21319636 has 12 divisors (see below), whose sum is σ = 40179412. Its totient is φ = 9839808.

The previous prime is 21319633. The next prime is 21319663. The reversal of 21319636 is 63691312.

It can be written as a sum of positive squares in 2 ways, for example, as 1123600 + 20196036 = 1060^2 + 4494^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21319598 and 21319607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21319633) by changing a digit.

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, 204945 + ... + 205048.

Almost surely, 2^21319636 is an apocalyptic number.

21319636 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21319636 is a deficient number, since it is larger than the sum of its proper divisors (18859776).

21319636 is a wasteful number, since it uses less digits than its factorization.

21319636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410010 (or 410008 counting only the distinct ones).

The product of its digits is 5832, while the sum is 31.

The square root of 21319636 is about 4617.3191356024. The cubic root of 21319636 is about 277.2851395289.

The spelling of 21319636 in words is "twenty-one million, three hundred nineteen thousand, six hundred thirty-six".