20745666 has 32 divisors (see below), whose sum is σ = 46414080. Its totient is φ = 6868368.

The previous prime is 20745649. The next prime is 20745667. The reversal of 20745666 is 66654702.

It is a self number, because there is not a number n which added to its sum of digits gives 20745666.

It is not an unprimeable number, because it can be changed into a prime (20745667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7255 + ... + 9701.

It is an arithmetic number, because the mean of its divisors is an integer number (1450440).

Almost surely, 2^20745666 is an apocalyptic number.

20745666 is an abundant number, since it is smaller than the sum of its proper divisors (25668414).

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

20745666 is a wasteful number, since it uses less digits than its factorization.

20745666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2615 (or 2609 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 20745666 is about 4554.7410464262. The cubic root of 20745666 is about 274.7740998835.

The spelling of 20745666 in words is "twenty million, seven hundred forty-five thousand, six hundred sixty-six".