165216125 has 8 divisors (see below), whose sum is σ = 206189880. Its totient is φ = 132172800.

The previous prime is 165216119. The next prime is 165216131. The reversal of 165216125 is 521612561.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (165216119) and next prime (165216131).

It can be written as a sum of positive squares in 4 ways, for example, as 31651876 + 133564249 = 5626^2 + 11557^2 .

It is not a de Polignac number, because 165216125 - 2¹⁶ = 165150589 is a prime.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 660740 + ... + 660989.

It is an arithmetic number, because the mean of its divisors is an integer number (25773735).

Almost surely, 2^165216125 is an apocalyptic number.

It is an amenable number.

165216125 is a deficient number, since it is larger than the sum of its proper divisors (40973755).

165216125 is an equidigital number, since it uses as much as digits as its factorization.

165216125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1321744 (or 1321734 counting only the distinct ones).

The product of its digits is 3600, while the sum is 29.

The square root of 165216125 is about 12853.6424798576. The cubic root of 165216125 is about 548.7200262788.

Adding to 165216125 its reverse (521612561), we get a palindrome (686828686).

The spelling of 165216125 in words is "one hundred sixty-five million, two hundred sixteen thousand, one hundred twenty-five".