2121154560 has 480 divisors, whose sum is σ = 8681944320. Its totient is φ = 481296384.

The previous prime is 2121154559. The next prime is 2121154579. The reversal of 2121154560 is 654511212.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15482812 + ... + 15482948.

It is an arithmetic number, because the mean of its divisors is an integer number (18087384).

Almost surely, 2^2121154560 is an apocalyptic number.

2121154560 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 2121154560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4340972160).

2121154560 is an abundant number, since it is smaller than the sum of its proper divisors (6560789760).

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

2121154560 is an equidigital number, since it uses as much as digits as its factorization.

2121154560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 2121154560 is about 46055.9937467427. The cubic root of 2121154560 is about 1284.8648204733.

Adding to 2121154560 its reverse (654511212), we get a palindrome (2775665772).

The spelling of 2121154560 in words is "two billion, one hundred twenty-one million, one hundred fifty-four thousand, five hundred sixty".