21689036 has 24 divisors (see below), whose sum is σ = 38623200. Its totient is φ = 10656000.

The previous prime is 21689029. The next prime is 21689047. The reversal of 21689036 is 63098612.

It is a junction number, because it is equal to n+sod(n) for n = 21688987 and 21689005.

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 7 ways as a sum of consecutive naturals, for example, 89876 + ... + 90116.

It is an arithmetic number, because the mean of its divisors is an integer number (1609300).

Almost surely, 2^21689036 is an apocalyptic number.

It is an amenable number.

21689036 is a deficient number, since it is larger than the sum of its proper divisors (16934164).

21689036 is a wasteful number, since it uses less digits than its factorization.

21689036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 21689036 is about 4657.1489132301. The cubic root of 21689036 is about 278.8774614651.

The spelling of 21689036 in words is "twenty-one million, six hundred eighty-nine thousand, thirty-six".