66406201 has 9 divisors (see below), whose sum is σ = 69020653. Its totient is φ = 63888160.

The previous prime is 66406181. The next prime is 66406237. The reversal of 66406201 is 10260466.

It is a happy number.

The square root of 66406201 is 8149.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 2725801 + 63680400 = 1651^2 + 7980^2 .

It is not a de Polignac number, because 66406201 - 2⁵ = 66406169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66406261) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 236181 + ... + 236461.

Almost surely, 2^66406201 is an apocalyptic number.

66406201 is the 8149-th square number.

66406201 is the 4075-th centered octagonal number.

It is an amenable number.

66406201 is a deficient number, since it is larger than the sum of its proper divisors (2614452).

66406201 is an frugal number, since it uses more digits than its factorization.

66406201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The cubic root of 66406201 is about 404.9513755575.

Multiplying 66406201 by its sum of digits (25), we get a square (1660155025 = 40745²).

Adding to 66406201 its reverse (10260466), we get a palindrome (76666667).

The spelling of 66406201 in words is "sixty-six million, four hundred six thousand, two hundred one".