187645993 has 2 divisors, whose sum is σ = 187645994. Its totient is φ = 187645992.

The previous prime is 187645967. The next prime is 187646003. The reversal of 187645993 is 399546781.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 103795344 + 83850649 = 10188^2 + 9157^2 .

It is an emirp because it is prime and its reverse (399546781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 187645993 - 2⁹ = 187645481 is a prime.

It is a super-2 number, since 2×187645993² = 70422037377912098, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 187645993.

It is not a weakly prime, because it can be changed into another prime (187645963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93822996 + 93822997.

It is an arithmetic number, because the mean of its divisors is an integer number (93822997).

Almost surely, 2^187645993 is an apocalyptic number.

It is an amenable number.

187645993 is a deficient number, since it is larger than the sum of its proper divisors (1).

187645993 is an equidigital number, since it uses as much as digits as its factorization.

187645993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 52.

The square root of 187645993 is about 13698.3938109546. The cubic root of 187645993 is about 572.5056340858.

The spelling of 187645993 in words is "one hundred eighty-seven million, six hundred forty-five thousand, nine hundred ninety-three".