187729121 has 2 divisors, whose sum is σ = 187729122. Its totient is φ = 187729120.

The previous prime is 187729117. The next prime is 187729141. The reversal of 187729121 is 121927781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166926400 + 20802721 = 12920^2 + 4561^2 .

It is a cyclic number.

It is not a de Polignac number, because 187729121 - 2² = 187729117 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (187729111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 93864560 + 93864561.

It is an arithmetic number, because the mean of its divisors is an integer number (93864561).

Almost surely, 2^187729121 is an apocalyptic number.

It is an amenable number.

187729121 is a deficient number, since it is larger than the sum of its proper divisors (1).

187729121 is an equidigital number, since it uses as much as digits as its factorization.

187729121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 38.

The square root of 187729121 is about 13701.4276993312. The cubic root of 187729121 is about 572.5901624426.

The spelling of 187729121 in words is "one hundred eighty-seven million, seven hundred twenty-nine thousand, one hundred twenty-one".