66251500 has 96 divisors (see below), whose sum is σ = 172763136. Its totient is φ = 21700800.

The previous prime is 66251489. The next prime is 66251501. The reversal of 66251500 is 515266.

It is a super-2 number, since 2×66251500² = 8778522504500000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (66251501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80089 + ... + 80911.

It is an arithmetic number, because the mean of its divisors is an integer number (1799616).

Almost surely, 2^66251500 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 66251500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86381568).

66251500 is an abundant number, since it is smaller than the sum of its proper divisors (106511636).

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

66251500 is a wasteful number, since it uses less digits than its factorization.

66251500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872 (or 860 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 66251500 is about 8139.5024417958. The cubic root of 66251500 is about 404.6366705439.

Adding to 66251500 its reverse (515266), we get a palindrome (66766766).

The spelling of 66251500 in words is "sixty-six million, two hundred fifty-one thousand, five hundred".