2163551940 has 288 divisors, whose sum is σ = 7442233344. Its totient is φ = 504218880.

The previous prime is 2163551939. The next prime is 2163551947. The reversal of 2163551940 is 491553612.

2163551940 is a `hidden beast` number, since 2 + 1 + 63 + 551 + 9 + 40 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 2163551895 and 2163551904.

It is not an unprimeable number, because it can be changed into a prime (2163551947) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6234847 + ... + 6235193.

It is an arithmetic number, because the mean of its divisors is an integer number (25841088).

Almost surely, 2^2163551940 is an apocalyptic number.

2163551940 is a gapful number since it is divisible by the number (20) 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 2163551940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3721116672).

2163551940 is an abundant number, since it is smaller than the sum of its proper divisors (5278681404).

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

2163551940 is a wasteful number, since it uses less digits than its factorization.

2163551940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487 (or 482 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 2163551940 is about 46513.9972481403. The cubic root of 2163551940 is about 1293.3689836479.

The spelling of 2163551940 in words is "two billion, one hundred sixty-three million, five hundred fifty-one thousand, nine hundred forty".