2161861632 has 528 divisors, whose sum is σ = 7847903232. Its totient is φ = 559595520.

The previous prime is 2161861631. The next prime is 2161861643. The reversal of 2161861632 is 2361681612.

It is a happy number.

2161861632 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 8 + 616 + 32 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (2161861631) 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, 45997033 + ... + 45997079.

Almost surely, 2^2161861632 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 2161861632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3923951616).

2161861632 is an abundant number, since it is smaller than the sum of its proper divisors (5686041600).

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

2161861632 is a wasteful number, since it uses less digits than its factorization.

2161861632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 113 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 2161861632 is about 46495.8238124673. The cubic root of 2161861632 is about 1293.0320744695.

The spelling of 2161861632 in words is "two billion, one hundred sixty-one million, eight hundred sixty-one thousand, six hundred thirty-two".