2161651872 has 48 divisors (see below), whose sum is σ = 5921052480. Its totient is φ = 689221632.

The previous prime is 2161651763. The next prime is 2161651873. The reversal of 2161651872 is 2781561612.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×2161651872² = 9345477631442208768, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2161651872.

It is not an unprimeable number, because it can be changed into a prime (2161651873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 487297 + ... + 491712.

It is an arithmetic number, because the mean of its divisors is an integer number (123355260).

Almost surely, 2^2161651872 is an apocalyptic number.

It is an amenable number.

2161651872 is an abundant number, since it is smaller than the sum of its proper divisors (3759400608).

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

2161651872 is a wasteful number, since it uses less digits than its factorization.

2161651872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979045 (or 979037 counting only the distinct ones).

The product of its digits is 40320, while the sum is 39.

The square root of 2161651872 is about 46493.5680712935. The cubic root of 2161651872 is about 1292.9902532329.

The spelling of 2161651872 in words is "two billion, one hundred sixty-one million, six hundred fifty-one thousand, eight hundred seventy-two".