188705389 has 8 divisors (see below), whose sum is σ = 200682360. Its totient is φ = 176825856.

The previous prime is 188705381. The next prime is 188705399. The reversal of 188705389 is 983507881.

It can be written as a sum of positive squares in 4 ways, for example, as 36602500 + 152102889 = 6050^2 + 12333^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 188705389 - 2³ = 188705381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (188705381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20344 + ... + 28129.

It is an arithmetic number, because the mean of its divisors is an integer number (25085295).

Almost surely, 2^188705389 is an apocalyptic number.

It is an amenable number.

188705389 is a deficient number, since it is larger than the sum of its proper divisors (11976971).

188705389 is a wasteful number, since it uses less digits than its factorization.

188705389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48719.

The product of its (nonzero) digits is 483840, while the sum is 49.

The square root of 188705389 is about 13737.0080075685. The cubic root of 188705389 is about 573.5810142753.

The spelling of 188705389 in words is "one hundred eighty-eight million, seven hundred five thousand, three hundred eighty-nine".