66153820 has 48 divisors (see below), whose sum is σ = 147692160. Its totient is φ = 24819264.

The previous prime is 66153803. The next prime is 66153883. The reversal of 66153820 is 2835166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39847 + ... + 41473.

It is an arithmetic number, because the mean of its divisors is an integer number (3076920).

Almost surely, 2^66153820 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 66153820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73846080).

66153820 is an abundant number, since it is smaller than the sum of its proper divisors (81538340).

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

66153820 is a wasteful number, since it uses less digits than its factorization.

66153820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762 (or 1760 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 66153820 is about 8133.4998616832. The cubic root of 66153820 is about 404.4377097614.

Adding to 66153820 its reverse (2835166), we get a palindrome (68988986).

The spelling of 66153820 in words is "sixty-six million, one hundred fifty-three thousand, eight hundred twenty".