207791351981 has 2 divisors, whose sum is σ = 207791351982. Its totient is φ = 207791351980.

The previous prime is 207791351959. The next prime is 207791352023. The reversal of 207791351981 is 189153197702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138005563081 + 69785788900 = 371491^2 + 264170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-207791351981 is a prime.

It is a super-2 number, since 2×207791351981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (207791351941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103895675990 + 103895675991.

It is an arithmetic number, because the mean of its divisors is an integer number (103895675991).

Almost surely, 2^207791351981 is an apocalyptic number.

It is an amenable number.

207791351981 is a deficient number, since it is larger than the sum of its proper divisors (1).

207791351981 is an equidigital number, since it uses as much as digits as its factorization.

207791351981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 952560, while the sum is 53.

The spelling of 207791351981 in words is "two hundred seven billion, seven hundred ninety-one million, three hundred fifty-one thousand, nine hundred eighty-one".