166387640 has 32 divisors (see below), whose sum is σ = 383082480. Its totient is φ = 65006592.

The previous prime is 166387607. The next prime is 166387643. The reversal of 166387640 is 46783661.

166387640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166387643) 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, 46649 + ... + 50088.

Almost surely, 2^166387640 is an apocalyptic number.

166387640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166387640 is an abundant number, since it is smaller than the sum of its proper divisors (216694840).

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

166387640 is a wasteful number, since it uses less digits than its factorization.

166387640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96791 (or 96787 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 166387640 is about 12899.1333042185. The cubic root of 166387640 is about 550.0139280219.

The spelling of 166387640 in words is "one hundred sixty-six million, three hundred eighty-seven thousand, six hundred forty".