20691768 has 16 divisors (see below), whose sum is σ = 51729480. Its totient is φ = 6897248.

The previous prime is 20691733. The next prime is 20691791. The reversal of 20691768 is 86719602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431055 + ... + 431102.

Almost surely, 2^20691768 is an apocalyptic number.

It is an amenable number.

20691768 is an abundant number, since it is smaller than the sum of its proper divisors (31037712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20691768 is a wasteful number, since it uses less digits than its factorization.

20691768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862166 (or 862162 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 20691768 is about 4548.8205064610. The cubic root of 20691768 is about 274.5359357866.

The spelling of 20691768 in words is "twenty million, six hundred ninety-one thousand, seven hundred sixty-eight".