1905123540 has 48 divisors (see below), whose sum is σ = 5615104320. Its totient is φ = 481294080.

The previous prime is 1905123533. The next prime is 1905123541. The reversal of 1905123540 is 453215091.

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

It is a junction number, because it is equal to n+sod(n) for n = 1905123498 and 1905123507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1905123541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 834441 + ... + 836720.

It is an arithmetic number, because the mean of its divisors is an integer number (116981340).

Almost surely, 2^1905123540 is an apocalyptic number.

1905123540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1905123540 is an abundant number, since it is smaller than the sum of its proper divisors (3709980780).

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

1905123540 is a wasteful number, since it uses less digits than its factorization.

1905123540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1671192 (or 1671190 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1905123540 is about 43647.7209027001. The cubic root of 1905123540 is about 1239.6746328089.

The spelling of 1905123540 in words is "one billion, nine hundred five million, one hundred twenty-three thousand, five hundred forty".