2181212893440 has 1440 divisors, whose sum is σ = 9351363969024. Its totient is φ = 474950615040.

The previous prime is 2181212893427. The next prime is 2181212893441. The reversal of 2181212893440 is 443982121812.

2181212893440 is a `hidden beast` number, since 2 + 1 + 8 + 1 + 21 + 289 + 344 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (2181212893441) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1507402797 + ... + 1507404243.

Almost surely, 2^{2181212893440} is an apocalyptic number.

2181212893440 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 2181212893440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4675681984512).

2181212893440 is an abundant number, since it is smaller than the sum of its proper divisors (7170151075584).

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

2181212893440 is a wasteful number, since it uses less digits than its factorization.

2181212893440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1585 (or 1562 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 2181212893440 in words is "two trillion, one hundred eighty-one billion, two hundred twelve million, eight hundred ninety-three thousand, four hundred forty".