6367981981 has 2 divisors, whose sum is σ = 6367981982. Its totient is φ = 6367981980.

The previous prime is 6367981973. The next prime is 6367982017. The reversal of 6367981981 is 1891897636.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6322635225 + 45346756 = 79515^2 + 6734^2 .

It is a cyclic number.

It is not a de Polignac number, because 6367981981 - 2³ = 6367981973 is a prime.

It is a super-2 number, since 2×6367981981² = 81102389020681368722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6367981931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3183990990 + 3183990991.

It is an arithmetic number, because the mean of its divisors is an integer number (3183990991).

Almost surely, 2^6367981981 is an apocalyptic number.

It is an amenable number.

6367981981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6367981981 is an equidigital number, since it uses as much as digits as its factorization.

6367981981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3919104, while the sum is 58.

The square root of 6367981981 is about 79799.6364716031. The cubic root of 6367981981 is about 1853.5342209274.

The spelling of 6367981981 in words is "six billion, three hundred sixty-seven million, nine hundred eighty-one thousand, nine hundred eighty-one".