66628401 has 16 divisors (see below), whose sum is σ = 105944064. Its totient is φ = 36417744.

The previous prime is 66628381. The next prime is 66628417. The reversal of 66628401 is 10482666.

It is a happy number.

It is not a de Polignac number, because 66628401 - 2⁷ = 66628273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66628451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68491 + ... + 69456.

It is an arithmetic number, because the mean of its divisors is an integer number (6621504).

Almost surely, 2^66628401 is an apocalyptic number.

It is an amenable number.

66628401 is a deficient number, since it is larger than the sum of its proper divisors (39315663).

66628401 is a wasteful number, since it uses less digits than its factorization.

66628401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137980.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 66628401 is about 8162.6221889782. The cubic root of 66628401 is about 405.4025383522.

The spelling of 66628401 in words is "sixty-six million, six hundred twenty-eight thousand, four hundred one".