21149056547 has 2 divisors, whose sum is σ = 21149056548. Its totient is φ = 21149056546.

The previous prime is 21149056543. The next prime is 21149056571. The reversal of 21149056547 is 74565094112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21149056547 - 2² = 21149056543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21149056498 and 21149056507.

It is not a weakly prime, because it can be changed into another prime (21149056543) 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, 10574528273 + 10574528274.

It is an arithmetic number, because the mean of its divisors is an integer number (10574528274).

Almost surely, 2^21149056547 is an apocalyptic number.

21149056547 is a deficient number, since it is larger than the sum of its proper divisors (1).

21149056547 is an equidigital number, since it uses as much as digits as its factorization.

21149056547 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 44.

The spelling of 21149056547 in words is "twenty-one billion, one hundred forty-nine million, fifty-six thousand, five hundred forty-seven".