1905840 has 60 divisors (see below), whose sum is σ = 6402864. Its totient is φ = 508032.

The previous prime is 1905821. The next prime is 1905863. The reversal of 1905840 is 485091.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×1905840² = 7264452211200, which contains 22 as substring.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 604 + ... + 2043.

2^1905840 is an apocalyptic number.

1905840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1905840 is an abundant number, since it is smaller than the sum of its proper divisors (4497024).

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

1905840 is a wasteful number, since it uses less digits than its factorization.

1905840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2666 (or 2657 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 1905840 is about 1380.5216405403. The cubic root of 1905840 is about 123.9830014853.

Subtracting from 1905840 its product of nonzero digits (1440), we obtain a square (1904400 = 1380²).

The spelling of 1905840 in words is "one million, nine hundred five thousand, eight hundred forty".