165212501 has 4 divisors (see below), whose sum is σ = 168329772. Its totient is φ = 162095232.

The previous prime is 165212497. The next prime is 165212503. The reversal of 165212501 is 105212561.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44542276 + 120670225 = 6674^2 + 10985^2 .

It is a cyclic number.

It is not a de Polignac number, because 165212501 - 2² = 165212497 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165212503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1558556 + ... + 1558661.

It is an arithmetic number, because the mean of its divisors is an integer number (42082443).

Almost surely, 2^165212501 is an apocalyptic number.

It is an amenable number.

165212501 is a deficient number, since it is larger than the sum of its proper divisors (3117271).

165212501 is an equidigital number, since it uses as much as digits as its factorization.

165212501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3117270.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 165212501 is about 12853.5015073714. The cubic root of 165212501 is about 548.7160142089.

The spelling of 165212501 in words is "one hundred sixty-five million, two hundred twelve thousand, five hundred one".