187118021 has 2 divisors, whose sum is σ = 187118022. Its totient is φ = 187118020.

The previous prime is 187118017. The next prime is 187118033. The reversal of 187118021 is 120811781.

187118021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98287396 + 88830625 = 9914^2 + 9425^2 .

It is a cyclic number.

It is not a de Polignac number, because 187118021 - 2² = 187118017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (187118221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93559010 + 93559011.

It is an arithmetic number, because the mean of its divisors is an integer number (93559011).

Almost surely, 2^187118021 is an apocalyptic number.

It is an amenable number.

187118021 is a deficient number, since it is larger than the sum of its proper divisors (1).

187118021 is an equidigital number, since it uses as much as digits as its factorization.

187118021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 29.

The square root of 187118021 is about 13679.1089256574. The cubic root of 187118021 is about 571.9681843275.

The spelling of 187118021 in words is "one hundred eighty-seven million, one hundred eighteen thousand, twenty-one".