891936691801 has 2 divisors, whose sum is σ = 891936691802. Its totient is φ = 891936691800.

The previous prime is 891936691799. The next prime is 891936691813. The reversal of 891936691801 is 108196639198.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 891936691776 + 25 = 944424^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 891936691801 - 2¹ = 891936691799 is a prime.

Together with 891936691799, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 891936691801.

It is not a weakly prime, because it can be changed into another prime (891936691501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445968345900 + 445968345901.

It is an arithmetic number, because the mean of its divisors is an integer number (445968345901).

Almost surely, 2^891936691801 is an apocalyptic number.

It is an amenable number.

891936691801 is a deficient number, since it is larger than the sum of its proper divisors (1).

891936691801 is an equidigital number, since it uses as much as digits as its factorization.

891936691801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5038848, while the sum is 61.

The spelling of 891936691801 in words is "eight hundred ninety-one billion, nine hundred thirty-six million, six hundred ninety-one thousand, eight hundred one".