165072561 has 8 divisors (see below), whose sum is σ = 220222464. Its totient is φ = 109985520.

The previous prime is 165072521. The next prime is 165072599. The reversal of 165072561 is 165270561.

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

It is not a de Polignac number, because 165072561 - 2⁷ = 165072433 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (165072521) 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, 9201 + ... + 20366.

It is an arithmetic number, because the mean of its divisors is an integer number (27527808).

Almost surely, 2^165072561 is an apocalyptic number.

It is an amenable number.

165072561 is a deficient number, since it is larger than the sum of its proper divisors (55149903).

165072561 is a wasteful number, since it uses less digits than its factorization.

165072561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31431.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 165072561 is about 12848.0567013070. The cubic root of 165072561 is about 548.5610440762.

The spelling of 165072561 in words is "one hundred sixty-five million, seventy-two thousand, five hundred sixty-one".