2161617408 has 160 divisors (see below), whose sum is σ = 6433278720. Its totient is φ = 716636160.

The previous prime is 2161617391. The next prime is 2161617413. The reversal of 2161617408 is 8047161612.

It is a happy number.

2161617408 is a `hidden beast` number, since 21 + 616 + 17 + 4 + 0 + 8 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3746016 + ... + 3746592.

It is an arithmetic number, because the mean of its divisors is an integer number (40207992).

Almost surely, 2^2161617408 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 2161617408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3216639360).

2161617408 is an abundant number, since it is smaller than the sum of its proper divisors (4271661312).

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

2161617408 is an equidigital number, since it uses as much as digits as its factorization.

2161617408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875 (or 853 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 2161617408 is about 46493.1974379048. The cubic root of 2161617408 is about 1292.9833816588.

The spelling of 2161617408 in words is "two billion, one hundred sixty-one million, six hundred seventeen thousand, four hundred eight".