1881728785 has 16 divisors (see below), whose sum is σ = 2369896704. Its totient is φ = 1431593152.

The previous prime is 1881728747. The next prime is 1881728789. The reversal of 1881728785 is 5878271881.

It is a cyclic number.

It is not a de Polignac number, because 1881728785 - 2²⁵ = 1848174353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1881728789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27397 + ... + 67186.

It is an arithmetic number, because the mean of its divisors is an integer number (148118544).

Almost surely, 2^1881728785 is an apocalyptic number.

It is an amenable number.

1881728785 is a deficient number, since it is larger than the sum of its proper divisors (488167919).

1881728785 is a wasteful number, since it uses less digits than its factorization.

1881728785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94784.

The product of its digits is 2007040, while the sum is 55.

The square root of 1881728785 is about 43378.8979228380. The cubic root of 1881728785 is about 1234.5793526630.

The spelling of 1881728785 in words is "one billion, eight hundred eighty-one million, seven hundred twenty-eight thousand, seven hundred eighty-five".