187969381 has 2 divisors, whose sum is σ = 187969382. Its totient is φ = 187969380.

The previous prime is 187969367. The next prime is 187969421. The reversal of 187969381 is 183969781.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167184900 + 20784481 = 12930^2 + 4559^2 .

It is a cyclic number.

It is not a de Polignac number, because 187969381 - 2¹⁵ = 187936613 is a prime.

It is a super-2 number, since 2×187969381² = 70664976387046322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (187969321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93984690 + 93984691.

It is an arithmetic number, because the mean of its divisors is an integer number (93984691).

Almost surely, 2^187969381 is an apocalyptic number.

It is an amenable number.

187969381 is a deficient number, since it is larger than the sum of its proper divisors (1).

187969381 is an equidigital number, since it uses as much as digits as its factorization.

187969381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 52.

The square root of 187969381 is about 13710.1925952920. The cubic root of 187969381 is about 572.8343296142.

The spelling of 187969381 in words is "one hundred eighty-seven million, nine hundred sixty-nine thousand, three hundred eighty-one".