187868381 has 2 divisors, whose sum is σ = 187868382. Its totient is φ = 187868380.

The previous prime is 187868363. The next prime is 187868423. The reversal of 187868381 is 183868781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133772356 + 54096025 = 11566^2 + 7355^2 .

It is a cyclic number.

It is not a de Polignac number, because 187868381 - 2²² = 183674077 is a prime.

It is a super-2 number, since 2×187868381² = 70589057159122322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (187868341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93934190 + 93934191.

It is an arithmetic number, because the mean of its divisors is an integer number (93934191).

Almost surely, 2^187868381 is an apocalyptic number.

It is an amenable number.

187868381 is a deficient number, since it is larger than the sum of its proper divisors (1).

187868381 is an equidigital number, since it uses as much as digits as its factorization.

187868381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 516096, while the sum is 50.

The square root of 187868381 is about 13706.5087093687. The cubic root of 187868381 is about 572.7317124884.

The spelling of 187868381 in words is "one hundred eighty-seven million, eight hundred sixty-eight thousand, three hundred eighty-one".