661023189 has 24 divisors (see below), whose sum is σ = 1018967040. Its totient is φ = 411481728.

The previous prime is 661023173. The next prime is 661023217. The reversal of 661023189 is 981320166.

661023189 is a `hidden beast` number, since 6 + 610 + 2 + 31 + 8 + 9 = 666.

It is not a de Polignac number, because 661023189 - 2⁴ = 661023173 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661023169) 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 in 23 ways as a sum of consecutive naturals, for example, 2422 + ... + 36440.

It is an arithmetic number, because the mean of its divisors is an integer number (42456960).

Almost surely, 2^661023189 is an apocalyptic number.

It is an amenable number.

661023189 is a deficient number, since it is larger than the sum of its proper divisors (357943851).

661023189 is a wasteful number, since it uses less digits than its factorization.

661023189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34169 (or 34166 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 661023189 is about 25710.3712341926. The cubic root of 661023189 is about 871.1084602864.

The spelling of 661023189 in words is "six hundred sixty-one million, twenty-three thousand, one hundred eighty-nine".