187109018721 has 27 divisors (see below), whose sum is σ = 282575370259. Its totient is φ = 119296863312.

The previous prime is 187109018711. The next prime is 187109018731. The reversal of 187109018721 is 127810901781.

The square root of 187109018721 is 432561.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (187109018711) and next prime (187109018731).

It can be written as a sum of positive squares in only one way, i.e., 59359962321 + 127749056400 = 243639^2 + 357420^2 .

It is not a de Polignac number, because 187109018721 - 2¹⁷ = 187108887649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (187109018711) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 29843575 + ... + 29849843.

Almost surely, 2^187109018721 is an apocalyptic number.

187109018721 is the 432561-st square number.

187109018721 is the 216281-st centered octagonal number.

It is an amenable number.

187109018721 is a deficient number, since it is larger than the sum of its proper divisors (95466351538).

187109018721 is an frugal number, since it uses more digits than its factorization.

187109018721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12590 (or 6295 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 45.

The spelling of 187109018721 in words is "one hundred eighty-seven billion, one hundred nine million, eighteen thousand, seven hundred twenty-one".