189105840 has 400 divisors, whose sum is σ = 821018880. Its totient is φ = 39191040.

The previous prime is 189105823. The next prime is 189105871. The reversal of 189105840 is 48501981.

It is a super-2 number, since 2×189105840² = 71522037444211200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 189105795 and 189105804.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 498771 + ... + 499149.

Almost surely, 2^189105840 is an apocalyptic number.

189105840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 189105840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410509440).

189105840 is an abundant number, since it is smaller than the sum of its proper divisors (631913040).

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

189105840 is a wasteful number, since it uses less digits than its factorization.

189105840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 189105840 is about 13751.5759096912. The cubic root of 189105840 is about 573.9864589877.

The spelling of 189105840 in words is "one hundred eighty-nine million, one hundred five thousand, eight hundred forty".