188961640 has 96 divisors (see below), whose sum is σ = 497917800. Its totient is φ = 64350720.

The previous prime is 188961599. The next prime is 188961671. The reversal of 188961640 is 46169881.

It can be written as a sum of positive squares in 4 ways, for example, as 135349956 + 53611684 = 11634^2 + 7322^2 .

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 23 ways as a sum of consecutive naturals, for example, 448630 + ... + 449050.

Almost surely, 2^188961640 is an apocalyptic number.

188961640 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 188961640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (248958900).

188961640 is an abundant number, since it is smaller than the sum of its proper divisors (308956160).

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

188961640 is a wasteful number, since it uses less digits than its factorization.

188961640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675 (or 664 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 188961640 is about 13746.3318743583. The cubic root of 188961640 is about 573.8405267866.

The spelling of 188961640 in words is "one hundred eighty-eight million, nine hundred sixty-one thousand, six hundred forty".