2161020540 has 288 divisors, whose sum is σ = 7361722368. Its totient is φ = 471744000.

The previous prime is 2161020529. The next prime is 2161020541. The reversal of 2161020540 is 450201612.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161020541) 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, 11939250 + ... + 11939430.

It is an arithmetic number, because the mean of its divisors is an integer number (25561536).

Almost surely, 2^2161020540 is an apocalyptic number.

2161020540 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 2161020540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3680861184).

2161020540 is an abundant number, since it is smaller than the sum of its proper divisors (5200701828).

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

2161020540 is a wasteful number, since it uses less digits than its factorization.

2161020540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 2161020540 is about 46486.7781202354. The cubic root of 2161020540 is about 1292.8643640744.

The spelling of 2161020540 in words is "two billion, one hundred sixty-one million, twenty thousand, five hundred forty".