66440931 has 8 divisors (see below), whose sum is σ = 89465424. Its totient is φ = 43855200.

The previous prime is 66440921. The next prime is 66440953. The reversal of 66440931 is 13904466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66440931 - 2¹⁵ = 66408163 is a prime.

It is a super-2 number, since 2×66440931² = 8828794624293522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 66440892 and 66440901.

It is not an unprimeable number, because it can be changed into a prime (66440911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109336 + ... + 109941.

It is an arithmetic number, because the mean of its divisors is an integer number (11183178).

Almost surely, 2^66440931 is an apocalyptic number.

66440931 is a deficient number, since it is larger than the sum of its proper divisors (23024493).

66440931 is a wasteful number, since it uses less digits than its factorization.

66440931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219381.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 66440931 is about 8151.1306577677. The cubic root of 66440931 is about 405.0219588764.

The spelling of 66440931 in words is "sixty-six million, four hundred forty thousand, nine hundred thirty-one".