66006403 has 4 divisors (see below), whose sum is σ = 66032800. Its totient is φ = 65980008.

The previous prime is 66006401. The next prime is 66006431. The reversal of 66006403 is 30460066.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66006403 - 2¹ = 66006401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66006401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9003 + ... + 14596.

It is an arithmetic number, because the mean of its divisors is an integer number (16508200).

Almost surely, 2^66006403 is an apocalyptic number.

66006403 is a deficient number, since it is larger than the sum of its proper divisors (26397).

66006403 is a wasteful number, since it uses less digits than its factorization.

66006403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26396.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 66006403 is about 8124.4324724869. The cubic root of 66006403 is about 404.1370703567.

Adding to 66006403 its reverse (30460066), we get a palindrome (96466469).

The spelling of 66006403 in words is "sixty-six million, six thousand, four hundred three".