161644559515 has 8 divisors (see below), whose sum is σ = 194063578848. Its totient is φ = 129255576000.

The previous prime is 161644559477. The next prime is 161644559519. The reversal of 161644559515 is 515955446161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-161644559515 is a prime.

It is a super-2 number, since 2×161644559515² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161644559519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7497111 + ... + 7518640.

It is an arithmetic number, because the mean of its divisors is an integer number (24257947356).

Almost surely, 2^161644559515 is an apocalyptic number.

161644559515 is a deficient number, since it is larger than the sum of its proper divisors (32419019333).

161644559515 is a wasteful number, since it uses less digits than its factorization.

161644559515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15017909.

The product of its digits is 3240000, while the sum is 52.

The spelling of 161644559515 in words is "one hundred sixty-one billion, six hundred forty-four million, five hundred fifty-nine thousand, five hundred fifteen".