161540015554 has 4 divisors (see below), whose sum is σ = 242310023334. Its totient is φ = 80770007776.

The previous prime is 161540015543. The next prime is 161540015573. The reversal of 161540015554 is 455510045161.

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

It can be written as a sum of positive squares in only one way, i.e., 141989544225 + 19550471329 = 376815^2 + 139823^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40385003887 + ... + 40385003890.

Almost surely, 2^161540015554 is an apocalyptic number.

161540015554 is a deficient number, since it is larger than the sum of its proper divisors (80770007780).

161540015554 is an equidigital number, since it uses as much as digits as its factorization.

161540015554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80770007779.

The product of its (nonzero) digits is 60000, while the sum is 37.

The spelling of 161540015554 in words is "one hundred sixty-one billion, five hundred forty million, fifteen thousand, five hundred fifty-four".