20666744 has 32 divisors (see below), whose sum is σ = 44728320. Its totient is φ = 8768736.

The previous prime is 20666743. The next prime is 20666759. The reversal of 20666744 is 44766602.

It is a happy number.

It is a super-2 number, since 2×20666744² = 854228615123072, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3977 + ... + 7559.

It is an arithmetic number, because the mean of its divisors is an integer number (1397760).

Almost surely, 2^20666744 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20666744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22364160).

20666744 is an abundant number, since it is smaller than the sum of its proper divisors (24061576).

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

20666744 is a wasteful number, since it uses less digits than its factorization.

20666744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3699 (or 3695 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 35.

The square root of 20666744 is about 4546.0690711867. The cubic root of 20666744 is about 274.4252193159.

It can be divided in two parts, 206 and 66744, that multiplied together give a square (13749264 = 3708²).

The spelling of 20666744 in words is "twenty million, six hundred sixty-six thousand, seven hundred forty-four".