21128530967 has 2 divisors, whose sum is σ = 21128530968. Its totient is φ = 21128530966.

The previous prime is 21128530939. The next prime is 21128530981. The reversal of 21128530967 is 76903582112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21128530967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21128530987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10564265483 + 10564265484.

It is an arithmetic number, because the mean of its divisors is an integer number (10564265484).

Almost surely, 2^21128530967 is an apocalyptic number.

21128530967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21128530967 is an equidigital number, since it uses as much as digits as its factorization.

21128530967 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 21128530967 in words is "twenty-one billion, one hundred twenty-eight million, five hundred thirty thousand, nine hundred sixty-seven".