187990442989 has 4 divisors (see below), whose sum is σ = 188294143840. Its totient is φ = 187686742140.

The previous prime is 187990442977. The next prime is 187990442999. The reversal of 187990442989 is 989244099781.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 187990442989 - 2¹¹ = 187990440941 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 (187990442909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151849497 + ... + 151850734.

It is an arithmetic number, because the mean of its divisors is an integer number (47073535960).

Almost surely, 2^187990442989 is an apocalyptic number.

It is an amenable number.

187990442989 is a deficient number, since it is larger than the sum of its proper divisors (303700851).

187990442989 is an equidigital number, since it uses as much as digits as its factorization.

187990442989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303700850.

The product of its (nonzero) digits is 94058496, while the sum is 70.

The spelling of 187990442989 in words is "one hundred eighty-seven billion, nine hundred ninety million, four hundred forty-two thousand, nine hundred eighty-nine".