187418921 has 2 divisors, whose sum is σ = 187418922. Its totient is φ = 187418920.

The previous prime is 187418893. The next prime is 187418929. The reversal of 187418921 is 129814781.

187418921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186704896 + 714025 = 13664^2 + 845^2 .

It is an emirp because it is prime and its reverse (129814781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 187418921 - 2¹⁸ = 187156777 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (187418929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93709460 + 93709461.

It is an arithmetic number, because the mean of its divisors is an integer number (93709461).

Almost surely, 2^187418921 is an apocalyptic number.

It is an amenable number.

187418921 is a deficient number, since it is larger than the sum of its proper divisors (1).

187418921 is an equidigital number, since it uses as much as digits as its factorization.

187418921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 41.

The square root of 187418921 is about 13690.1030310221. The cubic root of 187418921 is about 572.2746095724.

The spelling of 187418921 in words is "one hundred eighty-seven million, four hundred eighteen thousand, nine hundred twenty-one".