1681936641026 has 4 divisors (see below), whose sum is σ = 2522904961542. Its totient is φ = 840968320512.

The previous prime is 1681936640999. The next prime is 1681936641029. The reversal of 1681936641026 is 6201466391861.

It is a Cunningham number, because it is equal to 1296895²+1.

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

It can be written as a sum of positive squares in only one way, i.e., 1681936641025 + 1 = 1296895^2 + 1^2 .

It is not an unprimeable number, because it can be changed into a prime (1681936641029) by changing a digit.

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, 420484160255 + ... + 420484160258.

Almost surely, 2^{1681936641026} is an apocalyptic number.

1681936641026 is a deficient number, since it is larger than the sum of its proper divisors (840968320516).

1681936641026 is an equidigital number, since it uses as much as digits as its factorization.

1681936641026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840968320515.

The product of its (nonzero) digits is 2239488, while the sum is 53.

The spelling of 1681936641026 in words is "one trillion, six hundred eighty-one billion, nine hundred thirty-six million, six hundred forty-one thousand, twenty-six".