21428164547 has 2 divisors, whose sum is σ = 21428164548. Its totient is φ = 21428164546.

The previous prime is 21428164543. The next prime is 21428164619. The reversal of 21428164547 is 74546182412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21428164547 - 2² = 21428164543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21428164498 and 21428164507.

It is not a weakly prime, because it can be changed into another prime (21428164543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10714082273 + 10714082274.

It is an arithmetic number, because the mean of its divisors is an integer number (10714082274).

Almost surely, 2^21428164547 is an apocalyptic number.

21428164547 is a deficient number, since it is larger than the sum of its proper divisors (1).

21428164547 is an equidigital number, since it uses as much as digits as its factorization.

21428164547 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 430080, while the sum is 44.

The spelling of 21428164547 in words is "twenty-one billion, four hundred twenty-eight million, one hundred sixty-four thousand, five hundred forty-seven".