66440838 has 16 divisors (see below), whose sum is σ = 133024320. Its totient is φ = 22123176.

The previous prime is 66440837. The next prime is 66440839. The reversal of 66440838 is 83804466.

It is an interprime number because it is at equal distance from previous prime (66440837) and next prime (66440839).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66440796 and 66440805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66440837) 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, 681 + ... + 11547.

It is an arithmetic number, because the mean of its divisors is an integer number (8314020).

Almost surely, 2^66440838 is an apocalyptic number.

66440838 is an abundant number, since it is smaller than the sum of its proper divisors (66583482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66440838 is a wasteful number, since it uses less digits than its factorization.

66440838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11891.

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 66440838 is about 8151.1249530356. The cubic root of 66440838 is about 405.0217699013.

The spelling of 66440838 in words is "sixty-six million, four hundred forty thousand, eight hundred thirty-eight".