21719636 has 24 divisors (see below), whose sum is σ = 39842880. Its totient is φ = 10340352.

The previous prime is 21719597. The next prime is 21719647. The reversal of 21719636 is 63691712.

It is a junction number, because it is equal to n+sod(n) for n = 21719596 and 21719605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27860 + ... + 28628.

It is an arithmetic number, because the mean of its divisors is an integer number (1660120).

Almost surely, 2^21719636 is an apocalyptic number.

It is an amenable number.

21719636 is a deficient number, since it is larger than the sum of its proper divisors (18123244).

21719636 is a wasteful number, since it uses less digits than its factorization.

21719636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103 (or 1101 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 21719636 is about 4660.4330270909. The cubic root of 21719636 is about 279.0085513581.

The spelling of 21719636 in words is "twenty-one million, seven hundred nineteen thousand, six hundred thirty-six".