2161331928 has 192 divisors, whose sum is σ = 7133568000. Its totient is φ = 577414656.

The previous prime is 2161331911. The next prime is 2161331929. The reversal of 2161331928 is 8291331612.

2161331928 is a `hidden beast` number, since 2 + 1 + 613 + 3 + 19 + 28 = 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 a junction number, because it is equal to n+sod(n) for n = 2161331892 and 2161331901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161331929) 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, 755076 + ... + 757932.

It is an arithmetic number, because the mean of its divisors is an integer number (37154000).

Almost surely, 2^2161331928 is an apocalyptic number.

2161331928 is a gapful number since it is divisible by the number (28) 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 2161331928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3566784000).

2161331928 is an abundant number, since it is smaller than the sum of its proper divisors (4972236072).

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

2161331928 is a wasteful number, since it uses less digits than its factorization.

2161331928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2974 (or 2967 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 2161331928 is about 46490.1272099787. The cubic root of 2161331928 is about 1292.9264586737.

The spelling of 2161331928 in words is "two billion, one hundred sixty-one million, three hundred thirty-one thousand, nine hundred twenty-eight".