981778806431 has 2 divisors, whose sum is σ = 981778806432. Its totient is φ = 981778806430.

The previous prime is 981778806409. The next prime is 981778806527. The reversal of 981778806431 is 134608877189.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 981778806431 - 2⁶ = 981778806367 is a prime.

It is a super-2 number, since 2×981778806431² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (981778808431) 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, 490889403215 + 490889403216.

It is an arithmetic number, because the mean of its divisors is an integer number (490889403216).

Almost surely, 2^981778806431 is an apocalyptic number.

981778806431 is a deficient number, since it is larger than the sum of its proper divisors (1).

981778806431 is an equidigital number, since it uses as much as digits as its factorization.

981778806431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16257024, while the sum is 62.

The spelling of 981778806431 in words is "nine hundred eighty-one billion, seven hundred seventy-eight million, eight hundred six thousand, four hundred thirty-one".