2181961152 has 448 divisors, whose sum is σ = 7917972480. Its totient is φ = 582266880.

The previous prime is 2181961147. The next prime is 2181961153. The reversal of 2181961152 is 2511691812.

2181961152 is a `hidden beast` number, since 21 + 8 + 19 + 611 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (448).

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

Its product of digits (8640) is a multiple of the sum of its prime divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181961153) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16656127 + ... + 16656257.

Almost surely, 2^2181961152 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 2181961152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3958986240).

2181961152 is an abundant number, since it is smaller than the sum of its proper divisors (5736011328).

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

2181961152 is an equidigital number, since it uses as much as digits as its factorization.

2181961152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188 (or 160 counting only the distinct ones).

The product of its digits is 8640, while the sum is 36.

The square root of 2181961152 is about 46711.4670289855. The cubic root of 2181961152 is about 1297.0269637861.

The spelling of 2181961152 in words is "two billion, one hundred eighty-one million, nine hundred sixty-one thousand, one hundred fifty-two".