166809426 has 48 divisors (see below), whose sum is σ = 390071520. Its totient is φ = 47416320.

The previous prime is 166809413. The next prime is 166809437. The reversal of 166809426 is 624908661.

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

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, 60690 + ... + 63378.

It is an arithmetic number, because the mean of its divisors is an integer number (8126490).

Almost surely, 2^166809426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166809426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195035760).

166809426 is an abundant number, since it is smaller than the sum of its proper divisors (223262094).

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

166809426 is a wasteful number, since it uses less digits than its factorization.

166809426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2919 (or 2912 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 166809426 is about 12915.4723490858. The cubic root of 166809426 is about 550.4782902853.

It can be divided in two parts, 16680 and 9426, that added together give a triangular number (26106 = T₂₂₈).

The spelling of 166809426 in words is "one hundred sixty-six million, eight hundred nine thousand, four hundred twenty-six".