66402289 has 4 divisors (see below), whose sum is σ = 70308324. Its totient is φ = 62496256.

The previous prime is 66402251. The next prime is 66402319. The reversal of 66402289 is 98220466.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17640000 + 48762289 = 4200^2 + 6983^2 .

It is a cyclic number.

It is not a de Polignac number, because 66402289 - 2¹⁷ = 66271217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66402209) 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, 1952992 + ... + 1953025.

It is an arithmetic number, because the mean of its divisors is an integer number (17577081).

Almost surely, 2^66402289 is an apocalyptic number.

It is an amenable number.

66402289 is a deficient number, since it is larger than the sum of its proper divisors (3906035).

66402289 is a wasteful number, since it uses less digits than its factorization.

66402289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3906034.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 66402289 is about 8148.7599670134. The cubic root of 66402289 is about 404.9434234844.

The spelling of 66402289 in words is "sixty-six million, four hundred two thousand, two hundred eighty-nine".