165628989 has 32 divisors (see below), whose sum is σ = 251395200. Its totient is φ = 107740800.

The previous prime is 165628973. The next prime is 165629017. The reversal of 165628989 is 989826561.

It is a happy number.

165628989 is a `hidden beast` number, since 1 + 6 + 5 + 628 + 9 + 8 + 9 = 666.

It is not a de Polignac number, because 165628989 - 2⁴ = 165628973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165628919) 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 31 ways as a sum of consecutive naturals, for example, 275289 + ... + 275889.

It is an arithmetic number, because the mean of its divisors is an integer number (7856100).

Almost surely, 2^165628989 is an apocalyptic number.

It is an amenable number.

165628989 is a deficient number, since it is larger than the sum of its proper divisors (85766211).

165628989 is a wasteful number, since it uses less digits than its factorization.

165628989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 836 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The square root of 165628989 is about 12869.6926536728. The cubic root of 165628989 is about 549.1767175735.

The spelling of 165628989 in words is "one hundred sixty-five million, six hundred twenty-eight thousand, nine hundred eighty-nine".