161571271680 has 1056 divisors, whose sum is σ = 703000456704. Its totient is φ = 33400553472.

The previous prime is 161571271577. The next prime is 161571271703. The reversal of 161571271680 is 86172175161.

161571271680 is a `hidden beast` number, since 1 + 6 + 1 + 571 + 2 + 71 + 6 + 8 + 0 = 666.

It is a super-2 number, since 2×161571271680² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 95 ways as a sum of consecutive naturals, for example, 222243477 + ... + 222244203.

Almost surely, 2^161571271680 is an apocalyptic number.

161571271680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161571271680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (351500228352).

161571271680 is an abundant number, since it is smaller than the sum of its proper divisors (541429185024).

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

161571271680 is a wasteful number, since it uses less digits than its factorization.

161571271680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831 (or 810 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The spelling of 161571271680 in words is "one hundred sixty-one billion, five hundred seventy-one million, two hundred seventy-one thousand, six hundred eighty".