187427921 has 2 divisors, whose sum is σ = 187427922. Its totient is φ = 187427920.

The previous prime is 187427887. The next prime is 187427923. The reversal of 187427921 is 129724781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 177848896 + 9579025 = 13336^2 + 3095^2 .

It is a cyclic number.

It is not a de Polignac number, because 187427921 - 2¹⁴ = 187411537 is a prime.

Together with 187427923, 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 (187427923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93713960 + 93713961.

It is an arithmetic number, because the mean of its divisors is an integer number (93713961).

Almost surely, 2^187427921 is an apocalyptic number.

It is an amenable number.

187427921 is a deficient number, since it is larger than the sum of its proper divisors (1).

187427921 is an equidigital number, since it uses as much as digits as its factorization.

187427921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 41.

The square root of 187427921 is about 13690.4317316876. The cubic root of 187427921 is about 572.2837697807.

The spelling of 187427921 in words is "one hundred eighty-seven million, four hundred twenty-seven thousand, nine hundred twenty-one".