187989749 has 2 divisors, whose sum is σ = 187989750. Its totient is φ = 187989748.

The previous prime is 187989647. The next prime is 187989751. The reversal of 187989749 is 947989781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171138724 + 16851025 = 13082^2 + 4105^2 .

It is a cyclic number.

It is not a de Polignac number, because 187989749 - 2⁸ = 187989493 is a prime.

Together with 187989751, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 187989691 and 187989700.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (187989149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93994874 + 93994875.

It is an arithmetic number, because the mean of its divisors is an integer number (93994875).

Almost surely, 2^187989749 is an apocalyptic number.

It is an amenable number.

187989749 is a deficient number, since it is larger than the sum of its proper divisors (1).

187989749 is an equidigital number, since it uses as much as digits as its factorization.

187989749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9144576, while the sum is 62.

The square root of 187989749 is about 13710.9353801993. The cubic root of 187989749 is about 572.8550192751.

The spelling of 187989749 in words is "one hundred eighty-seven million, nine hundred eighty-nine thousand, seven hundred forty-nine".