128166990 has 64 divisors (see below), whose sum is σ = 352912896. Its totient is φ = 29181312.

The previous prime is 128166977. The next prime is 128166991. The reversal of 128166990 is 99661821.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128166991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60489 + ... + 62571.

It is an arithmetic number, because the mean of its divisors is an integer number (5514264).

Almost surely, 2^128166990 is an apocalyptic number.

128166990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 128166990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176456448).

128166990 is an abundant number, since it is smaller than the sum of its proper divisors (224745906).

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

128166990 is a wasteful number, since it uses less digits than its factorization.

128166990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2393.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 128166990 is about 11321.0860786410. The cubic root of 128166990 is about 504.1874853624.

The spelling of 128166990 in words is "one hundred twenty-eight million, one hundred sixty-six thousand, nine hundred ninety".