161515872 has 144 divisors (see below), whose sum is σ = 530318880. Its totient is φ = 45674496.

The previous prime is 161515853. The next prime is 161515883. The reversal of 161515872 is 278515161.

161515872 is a `hidden beast` number, since 1 + 61 + 515 + 87 + 2 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 227454 + ... + 228162.

It is an arithmetic number, because the mean of its divisors is an integer number (3682770).

Almost surely, 2^161515872 is an apocalyptic number.

161515872 is a gapful number since it is divisible by the number (12) 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 161515872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265159440).

161515872 is an abundant number, since it is smaller than the sum of its proper divisors (368803008).

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

161515872 is a wasteful number, since it uses less digits than its factorization.

161515872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 834 counting only the distinct ones).

The product of its digits is 16800, while the sum is 36.

The square root of 161515872 is about 12708.8894872841. The cubic root of 161515872 is about 544.5925996110.

The spelling of 161515872 in words is "one hundred sixty-one million, five hundred fifteen thousand, eight hundred seventy-two".