21400394167 has 2 divisors, whose sum is σ = 21400394168. Its totient is φ = 21400394166.

The previous prime is 21400394161. The next prime is 21400394201. The reversal of 21400394167 is 76149300412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21400394167 - 2⁷ = 21400394039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21400394161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700197083 + 10700197084.

It is an arithmetic number, because the mean of its divisors is an integer number (10700197084).

Almost surely, 2^21400394167 is an apocalyptic number.

21400394167 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400394167 is an equidigital number, since it uses as much as digits as its factorization.

21400394167 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 37.

Adding to 21400394167 its reverse (76149300412), we get a palindrome (97549694579).

The spelling of 21400394167 in words is "twenty-one billion, four hundred million, three hundred ninety-four thousand, one hundred sixty-seven".