161131203555 has 64 divisors (see below), whose sum is σ = 302549990400. Its totient is φ = 71691079680.

The previous prime is 161131203487. The next prime is 161131203587. The reversal of 161131203555 is 555302131161.

It is not a de Polignac number, because 161131203555 - 2¹³ = 161131195363 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1759131 + ... + 1848459.

It is an arithmetic number, because the mean of its divisors is an integer number (4727343600).

Almost surely, 2^161131203555 is an apocalyptic number.

161131203555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

161131203555 is a deficient number, since it is larger than the sum of its proper divisors (141418786845).

161131203555 is a wasteful number, since it uses less digits than its factorization.

161131203555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89804.

The product of its (nonzero) digits is 13500, while the sum is 33.

The spelling of 161131203555 in words is "one hundred sixty-one billion, one hundred thirty-one million, two hundred three thousand, five hundred fifty-five".