20666580 has 96 divisors (see below), whose sum is σ = 63842688. Its totient is φ = 4953600.

The previous prime is 20666573. The next prime is 20666599. The reversal of 20666580 is 8566602.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 31 ways as a sum of consecutive naturals, for example, 114090 + ... + 114270.

It is an arithmetic number, because the mean of its divisors is an integer number (665028).

Almost surely, 2^20666580 is an apocalyptic number.

20666580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20666580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31921344).

20666580 is an abundant number, since it is smaller than the sum of its proper divisors (43176108).

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

20666580 is a wasteful number, since it uses less digits than its factorization.

20666580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 375 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 20666580 is about 4546.0510335895. The cubic root of 20666580 is about 274.4244934178.

It can be divided in two parts, 2066 and 6580, that added together give a triangular number (8646 = T₁₃₁).

The spelling of 20666580 in words is "twenty million, six hundred sixty-six thousand, five hundred eighty".