66440255 has 16 divisors (see below), whose sum is σ = 92219904. Its totient is φ = 45008160.

The previous prime is 66440251. The next prime is 66440263. The reversal of 66440255 is 55204466.

It is not a de Polignac number, because 66440255 - 2² = 66440251 is a prime.

It is a super-4 number, since 4×66440255⁴ (a number of 32 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66440251) 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, 8531 + ... + 14340.

It is an arithmetic number, because the mean of its divisors is an integer number (5763744).

Almost surely, 2^66440255 is an apocalyptic number.

66440255 is a deficient number, since it is larger than the sum of its proper divisors (25779649).

66440255 is a wasteful number, since it uses less digits than its factorization.

66440255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22966.

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 66440255 is about 8151.0891910223. The cubic root of 66440255 is about 405.0205852464.

The spelling of 66440255 in words is "sixty-six million, four hundred forty thousand, two hundred fifty-five".