2161643525620 has 96 divisors (see below), whose sum is σ = 4673894400000. Its totient is φ = 839271014400.

The previous prime is 2161643525603. The next prime is 2161643525621. The reversal of 2161643525620 is 265253461612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161643525621) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244774605 + ... + 244783435.

It is an arithmetic number, because the mean of its divisors is an integer number (48686400000).

Almost surely, 2^{2161643525620} is an apocalyptic number.

2161643525620 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 2161643525620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2336947200000).

2161643525620 is an abundant number, since it is smaller than the sum of its proper divisors (2512250874380).

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

2161643525620 is a wasteful number, since it uses less digits than its factorization.

2161643525620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10369 (or 10367 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 2161643525620 in words is "two trillion, one hundred sixty-one billion, six hundred forty-three million, five hundred twenty-five thousand, six hundred twenty".