1861861860 has 72 divisors (see below), whose sum is σ = 5829847296. Its totient is φ = 480479040.

The previous prime is 1861861849. The next prime is 1861861873. The reversal of 1861861860 is 681681681.

1861861860 is a `hidden beast` number, since 18 + 6 + 18 + 618 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161254 + ... + 172413.

Almost surely, 2^1861861860 is an apocalyptic number.

1861861860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1861861860 is an abundant number, since it is smaller than the sum of its proper divisors (3967985436).

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

1861861860 is a wasteful number, since it uses less digits than its factorization.

1861861860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333713 (or 333708 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The square root of 1861861860 is about 43149.2973291571. The cubic root of 1861861860 is about 1230.2191558731.

The spelling of 1861861860 in words is "one billion, eight hundred sixty-one million, eight hundred sixty-one thousand, eight hundred sixty".