189861840 has 320 divisors, whose sum is σ = 774950400. Its totient is φ = 41803776.

The previous prime is 189861821. The next prime is 189861863. The reversal of 189861840 is 48168981.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 438264 + ... + 438696.

It is an arithmetic number, because the mean of its divisors is an integer number (2421720).

Almost surely, 2^189861840 is an apocalyptic number.

189861840 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 189861840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (387475200).

189861840 is an abundant number, since it is smaller than the sum of its proper divisors (585088560).

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

189861840 is a wasteful number, since it uses less digits than its factorization.

189861840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 479 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 189861840 is about 13779.0362507688. The cubic root of 189861840 is about 574.7503289089.

The spelling of 189861840 in words is "one hundred eighty-nine million, eight hundred sixty-one thousand, eight hundred forty".