1861936421895 has 48 divisors (see below), whose sum is σ = 3532221044352. Its totient is φ = 899816402880.

The previous prime is 1861936421867. The next prime is 1861936421911. The reversal of 1861936421895 is 5981246391681.

1861936421895 is a `hidden beast` number, since 1 + 8 + 619 + 3 + 6 + 4 + 2 + 1 + 8 + 9 + 5 = 666.

It is not a de Polignac number, because 1861936421895 - 2¹³ = 1861936413703 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5974237 + ... + 6278166.

It is an arithmetic number, because the mean of its divisors is an integer number (73587938424).

Almost surely, 2^{1861936421895} is an apocalyptic number.

1861936421895 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1861936421895 is a deficient number, since it is larger than the sum of its proper divisors (1670284622457).

1861936421895 is a wasteful number, since it uses less digits than its factorization.

1861936421895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12252732 (or 12252729 counting only the distinct ones).

The product of its digits is 22394880, while the sum is 63.

The spelling of 1861936421895 in words is "one trillion, eight hundred sixty-one billion, nine hundred thirty-six million, four hundred twenty-one thousand, eight hundred ninety-five".