1861846278078 has 32 divisors (see below), whose sum is σ = 3795181793280. Its totient is φ = 608810368320.

The previous prime is 1861846278077. The next prime is 1861846278107. The reversal of 1861846278078 is 8708726481681.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861846278077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13658968 + ... + 13794603.

It is an arithmetic number, because the mean of its divisors is an integer number (118599431040).

Almost surely, 2^{1861846278078} is an apocalyptic number.

1861846278078 is an abundant number, since it is smaller than the sum of its proper divisors (1933335515202).

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

1861846278078 is a wasteful number, since it uses less digits than its factorization.

1861846278078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27453792.

The product of its (nonzero) digits is 57802752, while the sum is 66.

The spelling of 1861846278078 in words is "one trillion, eight hundred sixty-one billion, eight hundred forty-six million, two hundred seventy-eight thousand, seventy-eight".