161556299956 has 6 divisors (see below), whose sum is σ = 282723524930. Its totient is φ = 80778149976.

The previous prime is 161556299929. The next prime is 161556299959. The reversal of 161556299956 is 659992655161.

It can be written as a sum of positive squares in only one way, i.e., 118450235556 + 43106064400 = 344166^2 + 207620^2 .

It is a super-2 number, since 2×161556299956² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161556299959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20194537491 + ... + 20194537498.

Almost surely, 2^161556299956 is an apocalyptic number.

It is an amenable number.

161556299956 is a deficient number, since it is larger than the sum of its proper divisors (121167224974).

161556299956 is a wasteful number, since it uses less digits than its factorization.

161556299956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40389074993 (or 40389074991 counting only the distinct ones).

The product of its digits is 39366000, while the sum is 64.

The spelling of 161556299956 in words is "one hundred sixty-one billion, five hundred fifty-six million, two hundred ninety-nine thousand, nine hundred fifty-six".