66909220 has 48 divisors (see below), whose sum is σ = 161360640. Its totient is φ = 22829184.

The previous prime is 66909217. The next prime is 66909223. The reversal of 66909220 is 2290966.

It is an interprime number because it is at equal distance from previous prime (66909217) and next prime (66909223).

It is not an unprimeable number, because it can be changed into a prime (66909223) 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, 31017 + ... + 33103.

It is an arithmetic number, because the mean of its divisors is an integer number (3361680).

Almost surely, 2^66909220 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 66909220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80680320).

66909220 is an abundant number, since it is smaller than the sum of its proper divisors (94451420).

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

66909220 is a wasteful number, since it uses less digits than its factorization.

66909220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2332 (or 2330 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 66909220 is about 8179.8056211624. The cubic root of 66909220 is about 405.9712906487.

The spelling of 66909220 in words is "sixty-six million, nine hundred nine thousand, two hundred twenty".