9967951421 has 2 divisors, whose sum is σ = 9967951422. Its totient is φ = 9967951420.

The previous prime is 9967951387. The next prime is 9967951423. The reversal of 9967951421 is 1241597699.

9967951421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5533723321 + 4434228100 = 74389^2 + 66590^2 .

It is a cyclic number.

It is not a de Polignac number, because 9967951421 - 2¹⁴ = 9967935037 is a prime.

Together with 9967951423, 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 (9967951423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4983975710 + 4983975711.

It is an arithmetic number, because the mean of its divisors is an integer number (4983975711).

Almost surely, 2^9967951421 is an apocalyptic number.

It is an amenable number.

9967951421 is a deficient number, since it is larger than the sum of its proper divisors (1).

9967951421 is an equidigital number, since it uses as much as digits as its factorization.

9967951421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1224720, while the sum is 53.

The square root of 9967951421 is about 99839.6285099259. The cubic root of 9967951421 is about 2152.1306745833.

The spelling of 9967951421 in words is "nine billion, nine hundred sixty-seven million, nine hundred fifty-one thousand, four hundred twenty-one".