189987840 has 528 divisors, whose sum is σ = 817489920. Its totient is φ = 39813120.

The previous prime is 189987827. The next prime is 189987851. The reversal of 189987840 is 48789981.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6128625 + ... + 6128655.

Almost surely, 2^189987840 is an apocalyptic number.

189987840 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 189987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (408744960).

189987840 is an abundant number, since it is smaller than the sum of its proper divisors (627502080).

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

189987840 is a wasteful number, since it uses less digits than its factorization.

189987840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 54.

The square root of 189987840 is about 13783.6076554725. The cubic root of 189987840 is about 574.8774433191.

The spelling of 189987840 in words is "one hundred eighty-nine million, nine hundred eighty-seven thousand, eight hundred forty".