20865668 has 12 divisors (see below), whose sum is σ = 36546972. Its totient is φ = 10423680.

The previous prime is 20865653. The next prime is 20865671. The reversal of 20865668 is 86656802.

It can be written as a sum of positive squares in 2 ways, for example, as 1435204 + 19430464 = 1198^2 + 4408^2 .

It is a super-2 number, since 2×20865668² = 870752202172448, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7328 + ... + 9768.

It is an arithmetic number, because the mean of its divisors is an integer number (3045581).

Almost surely, 2^20865668 is an apocalyptic number.

It is an amenable number.

20865668 is a deficient number, since it is larger than the sum of its proper divisors (15681304).

20865668 is a wasteful number, since it uses less digits than its factorization.

20865668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4582 (or 4580 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 41.

The square root of 20865668 is about 4567.8953578207. The cubic root of 20865668 is about 275.3028861122.

The spelling of 20865668 in words is "twenty million, eight hundred sixty-five thousand, six hundred sixty-eight".