165121649 has 8 divisors (see below), whose sum is σ = 205866048. Its totient is φ = 128666160.

The previous prime is 165121633. The next prime is 165121661. The reversal of 165121649 is 946121561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165121649 - 2⁴ = 165121633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165121699) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1072142 + ... + 1072295.

It is an arithmetic number, because the mean of its divisors is an integer number (25733256).

Almost surely, 2^165121649 is an apocalyptic number.

It is an amenable number.

165121649 is a deficient number, since it is larger than the sum of its proper divisors (40744399).

165121649 is a wasteful number, since it uses less digits than its factorization.

165121649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144455.

The product of its digits is 12960, while the sum is 35.

The square root of 165121649 is about 12849.9668871169. The cubic root of 165121649 is about 548.6154142990.

The spelling of 165121649 in words is "one hundred sixty-five million, one hundred twenty-one thousand, six hundred forty-nine".