20689635 has 16 divisors (see below), whose sum is σ = 33808896. Its totient is φ = 10799328.

The previous prime is 20689633. The next prime is 20689649. The reversal of 20689635 is 53698602.

It is not a de Polignac number, because 20689635 - 2¹ = 20689633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20689593 and 20689602.

It is not an unprimeable number, because it can be changed into a prime (20689633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13969 + ... + 15378.

It is an arithmetic number, because the mean of its divisors is an integer number (2113056).

Almost surely, 2^20689635 is an apocalyptic number.

20689635 is a deficient number, since it is larger than the sum of its proper divisors (13119261).

20689635 is a wasteful number, since it uses less digits than its factorization.

20689635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29402.

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 20689635 is about 4548.5860440361. The cubic root of 20689635 is about 274.5265019983.

The spelling of 20689635 in words is "twenty million, six hundred eighty-nine thousand, six hundred thirty-five".