165515810461 has 8 divisors (see below), whose sum is σ = 166307503320. Its totient is φ = 164725660992.

The previous prime is 165515810381. The next prime is 165515810479. The reversal of 165515810461 is 164018515561.

It can be written as a sum of positive squares in 4 ways, for example, as 132154787961 + 33361022500 = 363531^2 + 182650^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 165515810461 - 2⁷ = 165515810333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165515810491) 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, 170566 + ... + 600103.

It is an arithmetic number, because the mean of its divisors is an integer number (20788437915).

Almost surely, 2^165515810461 is an apocalyptic number.

It is an amenable number.

165515810461 is a deficient number, since it is larger than the sum of its proper divisors (791692859).

165515810461 is an equidigital number, since it uses as much as digits as its factorization.

165515810461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771695.

The product of its (nonzero) digits is 144000, while the sum is 43.

The spelling of 165515810461 in words is "one hundred sixty-five billion, five hundred fifteen million, eight hundred ten thousand, four hundred sixty-one".