165121501 has 4 divisors (see below), whose sum is σ = 165709404. Its totient is φ = 164533600.

The previous prime is 165121499. The next prime is 165121507. The reversal of 165121501 is 105121561.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 105121561 = 251 ⋅418811.

It can be written as a sum of positive squares in 2 ways, for example, as 98307225 + 66814276 = 9915^2 + 8174^2 .

It is a cyclic number.

It is not a de Polignac number, because 165121501 - 2¹ = 165121499 is a prime.

It is a super-2 number, since 2×165121501² = 54530220184986002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165121507) 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, 293530 + ... + 294091.

It is an arithmetic number, because the mean of its divisors is an integer number (41427351).

Almost surely, 2^165121501 is an apocalyptic number.

It is an amenable number.

165121501 is a deficient number, since it is larger than the sum of its proper divisors (587903).

165121501 is an equidigital number, since it uses as much as digits as its factorization.

165121501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587902.

The product of its (nonzero) digits is 300, while the sum is 22.

The square root of 165121501 is about 12849.9611283459. The cubic root of 165121501 is about 548.6152503894.

The spelling of 165121501 in words is "one hundred sixty-five million, one hundred twenty-one thousand, five hundred one".