187880081 has 4 divisors (see below), whose sum is σ = 192462564. Its totient is φ = 183297600.

The previous prime is 187880053. The next prime is 187880083. The reversal of 187880081 is 180088781.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76387600 + 111492481 = 8740^2 + 10559^2 .

It is a cyclic number.

It is not a de Polignac number, because 187880081 - 2¹⁰ = 187879057 is a prime.

It is a super-2 number, since 2×187880081² = 70597849673133122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 4582441 = 187880081 / (1 + 8 + 7 + 8 + 8 + 0 + 0 + 8 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (187880083) 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 3 ways as a sum of consecutive naturals, for example, 2291180 + ... + 2291261.

It is an arithmetic number, because the mean of its divisors is an integer number (48115641).

Almost surely, 2^187880081 is an apocalyptic number.

It is an amenable number.

187880081 is a deficient number, since it is larger than the sum of its proper divisors (4582483).

187880081 is an equidigital number, since it uses as much as digits as its factorization.

187880081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4582482.

The product of its (nonzero) digits is 28672, while the sum is 41.

The square root of 187880081 is about 13706.9355072533. The cubic root of 187880081 is about 572.7436017020.

The spelling of 187880081 in words is "one hundred eighty-seven million, eight hundred eighty thousand, eighty-one".