20995668 has 18 divisors (see below), whose sum is σ = 53072474. Its totient is φ = 6998544.

The previous prime is 20995657. The next prime is 20995693. The reversal of 20995668 is 86659902.

It can be written as a sum of positive squares in only one way, i.e., 20684304 + 311364 = 4548^2 + 558^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 291571 + ... + 291642.

Almost surely, 2^20995668 is an apocalyptic number.

It is an amenable number.

20995668 is an abundant number, since it is smaller than the sum of its proper divisors (32076806).

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

20995668 is a wasteful number, since it uses less digits than its factorization.

20995668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583223 (or 583218 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 20995668 is about 4582.1030106273. The cubic root of 20995668 is about 275.8734454453.

The spelling of 20995668 in words is "twenty million, nine hundred ninety-five thousand, six hundred sixty-eight".