20657768 has 16 divisors (see below), whose sum is σ = 39678660. Its totient is φ = 10076800.

The previous prime is 20657743. The next prime is 20657779. The reversal of 20657768 is 86775602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20052484 + 605284 = 4478^2 + 778^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

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 3 ways as a sum of consecutive naturals, for example, 31163 + ... + 31818.

Almost surely, 2^20657768 is an apocalyptic number.

It is an amenable number.

20657768 is a deficient number, since it is larger than the sum of its proper divisors (19020892).

20657768 is a wasteful number, since it uses less digits than its factorization.

20657768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63028 (or 63024 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 41.

The square root of 20657768 is about 4545.0817374388. The cubic root of 20657768 is about 274.3854840216.

The spelling of 20657768 in words is "twenty million, six hundred fifty-seven thousand, seven hundred sixty-eight".