66416840 has 32 divisors (see below), whose sum is σ = 170786880. Its totient is φ = 22771392.

The previous prime is 66416839. The next prime is 66416851. The reversal of 66416840 is 4861466.

It is a super-2 number, since 2×66416840² = 8822393271171200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 66416840.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118322 + ... + 118881.

It is an arithmetic number, because the mean of its divisors is an integer number (5337090).

Almost surely, 2^66416840 is an apocalyptic number.

It is an amenable number.

66416840 is an abundant number, since it is smaller than the sum of its proper divisors (104370040).

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

66416840 is a wasteful number, since it uses less digits than its factorization.

66416840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237221 (or 237217 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 66416840 is about 8149.6527533386. The cubic root of 66416840 is about 404.9730002831.

The spelling of 66416840 in words is "sixty-six million, four hundred sixteen thousand, eight hundred forty".