2145840 has 40 divisors (see below), whose sum is σ = 6652848. Its totient is φ = 572160.

The previous prime is 2145839. The next prime is 2145853. The reversal of 2145840 is 485412.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 2145840.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4231 + ... + 4710.

2^2145840 is an apocalyptic number.

2145840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2145840 is an abundant number, since it is smaller than the sum of its proper divisors (4507008).

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

2145840 is a wasteful number, since it uses less digits than its factorization.

2145840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8957 (or 8951 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 2145840 is about 1464.8685947893. The cubic root of 2145840 is about 128.9829915680.

The spelling of 2145840 in words is "two million, one hundred forty-five thousand, eight hundred forty".