187440721 has 8 divisors (see below), whose sum is σ = 202426560. Its totient is φ = 172535952.

The previous prime is 187440707. The next prime is 187440727. The reversal of 187440721 is 127044781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 187440721 - 2¹¹ = 187438673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (187440727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15415 + ... + 24748.

It is an arithmetic number, because the mean of its divisors is an integer number (25303320).

Almost surely, 2^187440721 is an apocalyptic number.

It is an amenable number.

187440721 is a deficient number, since it is larger than the sum of its proper divisors (14985839).

187440721 is a wasteful number, since it uses less digits than its factorization.

187440721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40535.

The product of its (nonzero) digits is 12544, while the sum is 34.

The square root of 187440721 is about 13690.8992034855. The cubic root of 187440721 is about 572.2967971273.

The spelling of 187440721 in words is "one hundred eighty-seven million, four hundred forty thousand, seven hundred twenty-one".