20666502 has 80 divisors (see below), whose sum is σ = 49397040. Its totient is φ = 6447168.

The previous prime is 20666453. The next prime is 20666521. The reversal of 20666502 is 20566602.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 248953 + ... + 249035.

It is an arithmetic number, because the mean of its divisors is an integer number (617463).

Almost surely, 2^20666502 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20666502, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24698520).

20666502 is an abundant number, since it is smaller than the sum of its proper divisors (28730538).

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

20666502 is a wasteful number, since it uses less digits than its factorization.

20666502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20666502 is about 4546.0424547072. The cubic root of 20666502 is about 274.4241481722.

The spelling of 20666502 in words is "twenty million, six hundred sixty-six thousand, five hundred two".