21058209919 has 2 divisors, whose sum is σ = 21058209920. Its totient is φ = 21058209918.

The previous prime is 21058209899. The next prime is 21058209929. The reversal of 21058209919 is 91990285012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21058209919 - 2³³ = 12468275327 is a prime.

It is a super-2 number, since 2×21058209919² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21058209929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10529104959 + 10529104960.

It is an arithmetic number, because the mean of its divisors is an integer number (10529104960).

Almost surely, 2^21058209919 is an apocalyptic number.

21058209919 is a deficient number, since it is larger than the sum of its proper divisors (1).

21058209919 is an equidigital number, since it uses as much as digits as its factorization.

21058209919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 46.

The spelling of 21058209919 in words is "twenty-one billion, fifty-eight million, two hundred nine thousand, nine hundred nineteen".