1861621823494 has 4 divisors (see below), whose sum is σ = 2792432735244. Its totient is φ = 930810911746.

The previous prime is 1861621823461. The next prime is 1861621823527. The reversal of 1861621823494 is 4943281261681.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1861621823461) and next prime (1861621823527).

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 as a sum of consecutive naturals, namely, 465405455872 + ... + 465405455875.

It is an arithmetic number, because the mean of its divisors is an integer number (698108183811).

Almost surely, 2^{1861621823494} is an apocalyptic number.

1861621823494 is a deficient number, since it is larger than the sum of its proper divisors (930810911750).

1861621823494 is an equidigital number, since it uses as much as digits as its factorization.

1861621823494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930810911749.

The product of its digits is 3981312, while the sum is 55.

The spelling of 1861621823494 in words is "one trillion, eight hundred sixty-one billion, six hundred twenty-one million, eight hundred twenty-three thousand, four hundred ninety-four".