21125050447 has 2 divisors, whose sum is σ = 21125050448. Its totient is φ = 21125050446.

The previous prime is 21125050439. The next prime is 21125050481. The reversal of 21125050447 is 74405052112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21125050447 - 2³ = 21125050439 is a prime.

It is a super-3 number, since 3×21125050447³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21125050417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562525223 + 10562525224.

It is an arithmetic number, because the mean of its divisors is an integer number (10562525224).

Almost surely, 2^21125050447 is an apocalyptic number.

21125050447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125050447 is an equidigital number, since it uses as much as digits as its factorization.

21125050447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11200, while the sum is 31.

The spelling of 21125050447 in words is "twenty-one billion, one hundred twenty-five million, fifty thousand, four hundred forty-seven".