187149491 has 2 divisors, whose sum is σ = 187149492. Its totient is φ = 187149490.

The previous prime is 187149439. The next prime is 187149493. The reversal of 187149491 is 194941781.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (194941781) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-187149491 is a prime.

It is a super-3 number, since 3×187149491³ (a number of 26 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 187149493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (187149493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93574745 + 93574746.

It is an arithmetic number, because the mean of its divisors is an integer number (93574746).

Almost surely, 2^187149491 is an apocalyptic number.

187149491 is a deficient number, since it is larger than the sum of its proper divisors (1).

187149491 is an equidigital number, since it uses as much as digits as its factorization.

187149491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 44.

The square root of 187149491 is about 13680.2591715216. The cubic root of 187149491 is about 572.0002475670. Note that the first 3 decimals are identical.

The spelling of 187149491 in words is "one hundred eighty-seven million, one hundred forty-nine thousand, four hundred ninety-one".