10091801981 has 2 divisors, whose sum is σ = 10091801982. Its totient is φ = 10091801980.

The previous prime is 10091801947. The next prime is 10091801983. The reversal of 10091801981 is 18910819001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8316528025 + 1775273956 = 91195^2 + 42134^2 .

It is an emirp because it is prime and its reverse (18910819001) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 18610816001 and 10061801681.

It is a cyclic number.

It is not a de Polignac number, because 10091801981 - 2⁶ = 10091801917 is a prime.

It is a super-2 number, since 2×10091801981² (a number of 21 digits) contains 22 as substring.

Together with 10091801983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10091801983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5045900990 + 5045900991.

It is an arithmetic number, because the mean of its divisors is an integer number (5045900991).

Almost surely, 2^10091801981 is an apocalyptic number.

It is an amenable number.

10091801981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10091801981 is an equidigital number, since it uses as much as digits as its factorization.

10091801981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 38.

The spelling of 10091801981 in words is "ten billion, ninety-one million, eight hundred one thousand, nine hundred eighty-one".