165045125451561 has 16 divisors (see below), whose sum is σ = 224742856635648. Its totient is φ = 107688750579200.

The previous prime is 165045125451553. The next prime is 165045125451637. The reversal of 165045125451561 is 165154521540561.

It is a cyclic number.

It is not a de Polignac number, because 165045125451561 - 2³ = 165045125451553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165045125451061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66871321 + ... + 69295481.

It is an arithmetic number, because the mean of its divisors is an integer number (14046428539728).

Almost surely, 2^{165045125451561} is an apocalyptic number.

It is an amenable number.

165045125451561 is a deficient number, since it is larger than the sum of its proper divisors (59697731184087).

165045125451561 is a wasteful number, since it uses less digits than its factorization.

165045125451561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2907072.

The product of its (nonzero) digits is 3600000, while the sum is 51.

The spelling of 165045125451561 in words is "one hundred sixty-five trillion, forty-five billion, one hundred twenty-five million, four hundred fifty-one thousand, five hundred sixty-one".