20665944 has 48 divisors (see below), whose sum is σ = 60278400. Its totient is φ = 6358464.

The previous prime is 20665907. The next prime is 20665961. The reversal of 20665944 is 44956602.

20665944 is a `hidden beast` number, since 2 + 0 + 66 + 594 + 4 = 666.

It is a super-2 number, since 2×20665944² = 854162482822272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20665899 and 20665908.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 10104 + ... + 11975.

It is an arithmetic number, because the mean of its divisors is an integer number (1255800).

Almost surely, 2^20665944 is an apocalyptic number.

20665944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20665944 is an abundant number, since it is smaller than the sum of its proper divisors (39612456).

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

20665944 is a wasteful number, since it uses less digits than its factorization.

20665944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22104 (or 22097 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 20665944 is about 4545.9810822308. The cubic root of 20665944 is about 274.4216783129.

It can be divided in two parts, 20665 and 944, that added together give a square (21609 = 147²).

The spelling of 20665944 in words is "twenty million, six hundred sixty-five thousand, nine hundred forty-four".