161755527515 has 4 divisors (see below), whose sum is σ = 194106633024. Its totient is φ = 129404422008.

The previous prime is 161755527511. The next prime is 161755527569. The reversal of 161755527515 is 515725557161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161755527515 - 2² = 161755527511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161755527511) 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, 16175552747 + ... + 16175552756.

It is an arithmetic number, because the mean of its divisors is an integer number (48526658256).

Almost surely, 2^161755527515 is an apocalyptic number.

161755527515 is a deficient number, since it is larger than the sum of its proper divisors (32351105509).

161755527515 is an equidigital number, since it uses as much as digits as its factorization.

161755527515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32351105508.

The product of its digits is 1837500, while the sum is 50.

The spelling of 161755527515 in words is "one hundred sixty-one billion, seven hundred fifty-five million, five hundred twenty-seven thousand, five hundred fifteen".