66840156 has 36 divisors (see below), whose sum is σ = 171826200. Its totient is φ = 21901728.

The previous prime is 66840133. The next prime is 66840161. The reversal of 66840156 is 65104866.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 66840156.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13611 + ... + 17858.

It is an arithmetic number, because the mean of its divisors is an integer number (4772950).

Almost surely, 2^66840156 is an apocalyptic number.

It is an amenable number.

66840156 is an abundant number, since it is smaller than the sum of its proper divisors (104986044).

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

66840156 is a wasteful number, since it uses less digits than its factorization.

66840156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31538 (or 31533 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 66840156 is about 8175.5829149976. The cubic root of 66840156 is about 405.8315607593.

The spelling of 66840156 in words is "sixty-six million, eight hundred forty thousand, one hundred fifty-six".