161509887215 has 4 divisors (see below), whose sum is σ = 193811864664. Its totient is φ = 129207909768.

The previous prime is 161509887197. The next prime is 161509887223. The reversal of 161509887215 is 512788905161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161509887215 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 16150988717 + ... + 16150988726.

It is an arithmetic number, because the mean of its divisors is an integer number (48452966166).

Almost surely, 2^161509887215 is an apocalyptic number.

161509887215 is a deficient number, since it is larger than the sum of its proper divisors (32301977449).

161509887215 is an equidigital number, since it uses as much as digits as its factorization.

161509887215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32301977448.

The product of its (nonzero) digits is 1209600, while the sum is 53.

The spelling of 161509887215 in words is "one hundred sixty-one billion, five hundred nine million, eight hundred eighty-seven thousand, two hundred fifteen".