2145281904 has 120 divisors (see below), whose sum is σ = 6213196080. Its totient is φ = 690453504.

The previous prime is 2145281903. The next prime is 2145281927. The reversal of 2145281904 is 4091825412.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145281903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 728467 + ... + 731405.

It is an arithmetic number, because the mean of its divisors is an integer number (51776634).

Almost surely, 2^2145281904 is an apocalyptic number.

2145281904 is a gapful number since it is divisible by the number (24) 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 2145281904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3106598040).

2145281904 is an abundant number, since it is smaller than the sum of its proper divisors (4067914176).

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

2145281904 is a wasteful number, since it uses less digits than its factorization.

2145281904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3127 (or 3118 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 2145281904 is about 46317.1879975458. The cubic root of 2145281904 is about 1289.7180851412.

The spelling of 2145281904 in words is "two billion, one hundred forty-five million, two hundred eighty-one thousand, nine hundred four".