69971981 has 2 divisors, whose sum is σ = 69971982. Its totient is φ = 69971980.

The previous prime is 69971971. The next prime is 69971989. The reversal of 69971981 is 18917996.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59923081 + 10048900 = 7741^2 + 3170^2 .

It is a cyclic number.

It is not a de Polignac number, because 69971981 - 2¹⁴ = 69955597 is a prime.

It is a super-2 number, since 2×69971981² = 9792156250128722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (69971989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34985990 + 34985991.

It is an arithmetic number, because the mean of its divisors is an integer number (34985991).

Almost surely, 2^69971981 is an apocalyptic number.

It is an amenable number.

69971981 is a deficient number, since it is larger than the sum of its proper divisors (1).

69971981 is an equidigital number, since it uses as much as digits as its factorization.

69971981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 50.

The square root of 69971981 is about 8364.9256422278. The cubic root of 69971981 is about 412.0735348841.

The spelling of 69971981 in words is "sixty-nine million, nine hundred seventy-one thousand, nine hundred eighty-one".