66106440 has 96 divisors (see below), whose sum is σ = 219473280. Its totient is φ = 17248896.

The previous prime is 66106433. The next prime is 66106483. The reversal of 66106440 is 4460166.

66106440 is a `hidden beast` number, since 6 + 6 + 10 + 644 + 0 = 666.

It is a super-2 number, since 2×66106440² = 8740122818947200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14967 + ... + 18873.

It is an arithmetic number, because the mean of its divisors is an integer number (2286180).

Almost surely, 2^66106440 is an apocalyptic number.

66106440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66106440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109736640).

66106440 is an abundant number, since it is smaller than the sum of its proper divisors (153366840).

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

66106440 is a wasteful number, since it uses less digits than its factorization.

66106440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3971 (or 3964 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 66106440 is about 8130.5866946980. The cubic root of 66106440 is about 404.3411326464.

The spelling of 66106440 in words is "sixty-six million, one hundred six thousand, four hundred forty".