21050570447 has 2 divisors, whose sum is σ = 21050570448. Its totient is φ = 21050570446.

The previous prime is 21050570441. The next prime is 21050570449. The reversal of 21050570447 is 74407505012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21050570447 - 2¹² = 21050566351 is a prime.

It is a super-4 number, since 4×21050570447⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 21050570449, 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 (21050570441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525285223 + 10525285224.

It is an arithmetic number, because the mean of its divisors is an integer number (10525285224).

Almost surely, 2^21050570447 is an apocalyptic number.

21050570447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21050570447 is an equidigital number, since it uses as much as digits as its factorization.

21050570447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39200, while the sum is 35.

The spelling of 21050570447 in words is "twenty-one billion, fifty million, five hundred seventy thousand, four hundred forty-seven".