1861094417778 has 12 divisors (see below), whose sum is σ = 4032371238558. Its totient is φ = 620364805920.

The previous prime is 1861094417719. The next prime is 1861094417779. The reversal of 1861094417778 is 8777144901681.

1861094417778 is a `hidden beast` number, since 1 + 8 + 61 + 0 + 94 + 417 + 7 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1859533140609 + 1561277169 = 1363647^2 + 39513^2 .

It is not an unprimeable number, because it can be changed into a prime (1861094417779) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51697067143 + ... + 51697067178.

Almost surely, 2^{1861094417778} is an apocalyptic number.

1861094417778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1861094417778 is an abundant number, since it is smaller than the sum of its proper divisors (2171276820780).

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

1861094417778 is a wasteful number, since it uses less digits than its factorization.

1861094417778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103394134329 (or 103394134326 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 63.

The spelling of 1861094417778 in words is "one trillion, eight hundred sixty-one billion, ninety-four million, four hundred seventeen thousand, seven hundred seventy-eight".