189991872 has 224 divisors, whose sum is σ = 648614400. Its totient is φ = 53415936.

The previous prime is 189991871. The next prime is 189991883. The reversal of 189991872 is 278199981.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×189991872² = 72193822852128768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189991871) 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, 1366779 + ... + 1366917.

It is an arithmetic number, because the mean of its divisors is an integer number (2895600).

Almost surely, 2^189991872 is an apocalyptic number.

189991872 is a gapful number since it is divisible by the number (12) 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 189991872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324307200).

189991872 is an abundant number, since it is smaller than the sum of its proper divisors (458622528).

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

189991872 is a wasteful number, since it uses less digits than its factorization.

189991872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 264 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 189991872 is about 13783.7539153889. The cubic root of 189991872 is about 574.8815100521.

The spelling of 189991872 in words is "one hundred eighty-nine million, nine hundred ninety-one thousand, eight hundred seventy-two".