2145121680 has 320 divisors, whose sum is σ = 7559516160. Its totient is φ = 499243008.

The previous prime is 2145121673. The next prime is 2145121691. The reversal of 2145121680 is 861215412.

It is a super-3 number, since 3×2145121680³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11983831 + ... + 11984009.

It is an arithmetic number, because the mean of its divisors is an integer number (23623488).

Almost surely, 2^2145121680 is an apocalyptic number.

2145121680 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 2145121680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3779758080).

2145121680 is an abundant number, since it is smaller than the sum of its proper divisors (5414394480).

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

2145121680 is a wasteful number, since it uses less digits than its factorization.

2145121680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398 (or 392 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 2145121680 is about 46315.4583265674. The cubic root of 2145121680 is about 1289.6859760844.

The spelling of 2145121680 in words is "two billion, one hundred forty-five million, one hundred twenty-one thousand, six hundred eighty".