161761508541 has 40 divisors (see below), whose sum is σ = 252230799744. Its totient is φ = 103119207840.

The previous prime is 161761508507. The next prime is 161761508543. The reversal of 161761508541 is 145805167161.

161761508541 is a `hidden beast` number, since 16 + 17 + 615 + 0 + 8 + 5 + 4 + 1 = 666.

It is not a de Polignac number, because 161761508541 - 2⁶ = 161761508477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161761508543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 6659280 + ... + 6683526.

Almost surely, 2^161761508541 is an apocalyptic number.

It is an amenable number.

161761508541 is a deficient number, since it is larger than the sum of its proper divisors (90469291203).

161761508541 is a wasteful number, since it uses less digits than its factorization.

161761508541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27863 (or 27854 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The spelling of 161761508541 in words is "one hundred sixty-one billion, seven hundred sixty-one million, five hundred eight thousand, five hundred forty-one".