66001000 has 64 divisors (see below), whose sum is σ = 166355280. Its totient is φ = 24364800.

The previous prime is 66000997. The next prime is 66001027. The reversal of 66001000 is 10066.

It can be written as a sum of positive squares in 8 ways, for example, as 5503716 + 60497284 = 2346^2 + 7778^2 .

It is a super-2 number, since 2×66001000² = 8712264002000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

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, 10462 + ... + 15538.

Almost surely, 2^66001000 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 66001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83177640).

66001000 is an abundant number, since it is smaller than the sum of its proper divisors (100354280).

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

66001000 is a wasteful number, since it uses less digits than its factorization.

66001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5111 (or 5097 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 66001000 is about 8124.0999501483. The cubic root of 66001000 is about 404.1260430822.

Adding to 66001000 its reverse (10066), we get a palindrome (66011066).

It can be divided in two parts, 6 and 6001000, that added together give a palindrome (6001006).

The spelling of 66001000 in words is "sixty-six million, one thousand".