1861787120 has 20 divisors (see below), whose sum is σ = 4328655240. Its totient is φ = 744714816.

The previous prime is 1861787117. The next prime is 1861787131. The reversal of 1861787120 is 217871681.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11636090 + ... + 11636249.

It is an arithmetic number, because the mean of its divisors is an integer number (216432762).

Almost surely, 2^1861787120 is an apocalyptic number.

1861787120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1861787120 is an abundant number, since it is smaller than the sum of its proper divisors (2466868120).

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

1861787120 is a wasteful number, since it uses less digits than its factorization.

1861787120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23272352 (or 23272346 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 41.

The square root of 1861787120 is about 43148.4312576946. The cubic root of 1861787120 is about 1230.2026942491.

The spelling of 1861787120 in words is "one billion, eight hundred sixty-one million, seven hundred eighty-seven thousand, one hundred twenty".