66511001 has 6 divisors (see below), whose sum is σ = 70196202. Its totient is φ = 63010080.

The previous prime is 66510991. The next prime is 66511019. The reversal of 66511001 is 10011566.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 58920976 + 7590025 = 7676^2 + 2755^2 .

It is not a de Polignac number, because 66511001 - 2⁶ = 66510937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66511031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 91760 + ... + 92481.

It is an arithmetic number, because the mean of its divisors is an integer number (11699367).

Almost surely, 2^66511001 is an apocalyptic number.

It is an amenable number.

66511001 is a deficient number, since it is larger than the sum of its proper divisors (3685201).

66511001 is a wasteful number, since it uses less digits than its factorization.

66511001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184279 (or 184260 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 66511001 is about 8155.4277018437. The cubic root of 66511001 is about 405.1642904051.

Adding to 66511001 its reverse (10011566), we get a palindrome (76522567).

The spelling of 66511001 in words is "sixty-six million, five hundred eleven thousand, one".