161997560043 has 16 divisors (see below), whose sum is σ = 235711216512. Its totient is φ = 98147672000.

The previous prime is 161997560027. The next prime is 161997560057. The reversal of 161997560043 is 340065799161.

It is a cyclic number.

It is not a de Polignac number, because 161997560043 - 2⁴ = 161997560027 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161997560843) 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 15 ways as a sum of consecutive naturals, for example, 715818 + ... + 914543.

It is an arithmetic number, because the mean of its divisors is an integer number (14731951032).

Almost surely, 2^161997560043 is an apocalyptic number.

161997560043 is a deficient number, since it is larger than the sum of its proper divisors (73713656469).

161997560043 is a wasteful number, since it uses less digits than its factorization.

161997560043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633386.

The product of its (nonzero) digits is 1224720, while the sum is 51.

The spelling of 161997560043 in words is "one hundred sixty-one billion, nine hundred ninety-seven million, five hundred sixty thousand, forty-three".