20689799 has 12 divisors (see below), whose sum is σ = 23673384. Its totient is φ = 17971584.

The previous prime is 20689787. The next prime is 20689807. The reversal of 20689799 is 99798602.

It is a de Polignac number, because none of the positive numbers 2^k-20689799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1004 + ... + 6510.

It is an arithmetic number, because the mean of its divisors is an integer number (1972782).

Almost surely, 2^20689799 is an apocalyptic number.

20689799 is a deficient number, since it is larger than the sum of its proper divisors (2983585).

20689799 is a wasteful number, since it uses less digits than its factorization.

20689799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5554 (or 5537 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 20689799 is about 4548.6040715806. The cubic root of 20689799 is about 274.5272273571.

The spelling of 20689799 in words is "twenty million, six hundred eighty-nine thousand, seven hundred ninety-nine".