161265021 has 8 divisors (see below), whose sum is σ = 215095104. Its totient is φ = 107472480.

The previous prime is 161264953. The next prime is 161265031. The reversal of 161265021 is 120562161.

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

It is not a de Polignac number, because 161265021 - 2¹⁰ = 161263997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161264982 and 161265000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161265031) 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 7 ways as a sum of consecutive naturals, for example, 2961 + ... + 18201.

It is an arithmetic number, because the mean of its divisors is an integer number (26886888).

Almost surely, 2^161265021 is an apocalyptic number.

It is an amenable number.

161265021 is a deficient number, since it is larger than the sum of its proper divisors (53830083).

161265021 is a wasteful number, since it uses less digits than its factorization.

161265021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18771.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 161265021 is about 12699.0165367244. The cubic root of 161265021 is about 544.3105171514.

The spelling of 161265021 in words is "one hundred sixty-one million, two hundred sixty-five thousand, twenty-one".