161518446864 has 240 divisors, whose sum is σ = 490198625280. Its totient is φ = 49493283840.

The previous prime is 161518446863. The next prime is 161518446877. The reversal of 161518446864 is 468644815161.

161518446864 is a `hidden beast` number, since 1 + 6 + 1 + 518 + 4 + 4 + 68 + 64 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 161518446864.

It is not an unprimeable number, because it can be changed into a prime (161518446863) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21414934 + ... + 21422474.

It is an arithmetic number, because the mean of its divisors is an integer number (2042494272).

Almost surely, 2^161518446864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161518446864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245099312640).

161518446864 is an abundant number, since it is smaller than the sum of its proper divisors (328680178416).

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

161518446864 is a wasteful number, since it uses less digits than its factorization.

161518446864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7830 (or 7821 counting only the distinct ones).

The product of its digits is 4423680, while the sum is 54.

The spelling of 161518446864 in words is "one hundred sixty-one billion, five hundred eighteen million, four hundred forty-six thousand, eight hundred sixty-four".