161555135616 has 144 divisors (see below), whose sum is σ = 540792611190. Its totient is φ = 46158594048.

The previous prime is 161555135591. The next prime is 161555135633. The reversal of 161555135616 is 616531555161.

161555135616 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 551 + 35 + 61 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 143265278016 + 18289857600 = 378504^2 + 135240^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-3 number, since 3×161555135616³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1374561 + ... + 1487456.

Almost surely, 2^161555135616 is an apocalyptic number.

161555135616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161555135616 is an abundant number, since it is smaller than the sum of its proper divisors (379237475574).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161555135616 is a wasteful number, since it uses less digits than its factorization.

161555135616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2862051 (or 2862029 counting only the distinct ones).

The product of its digits is 405000, while the sum is 45.

The spelling of 161555135616 in words is "one hundred sixty-one billion, five hundred fifty-five million, one hundred thirty-five thousand, six hundred sixteen".