921090187 has 2 divisors, whose sum is σ = 921090188. Its totient is φ = 921090186.

The previous prime is 921090097. The next prime is 921090239. The reversal of 921090187 is 781090129.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 921090187 - 2⁷ = 921090059 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (921090587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460545093 + 460545094.

It is an arithmetic number, because the mean of its divisors is an integer number (460545094).

Almost surely, 2^921090187 is an apocalyptic number.

921090187 is a deficient number, since it is larger than the sum of its proper divisors (1).

921090187 is an equidigital number, since it uses as much as digits as its factorization.

921090187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 921090187 is about 30349.4676559573. The cubic root of 921090187 is about 972.9728425794.

The spelling of 921090187 in words is "nine hundred twenty-one million, ninety thousand, one hundred eighty-seven".