21000555319 has 2 divisors, whose sum is σ = 21000555320. Its totient is φ = 21000555318.

The previous prime is 21000555307. The next prime is 21000555377. The reversal of 21000555319 is 91355500012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000555319 - 2⁹ = 21000554807 is a prime.

It is a super-2 number, since 2×21000555319² (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 (21000555419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500277659 + 10500277660.

It is an arithmetic number, because the mean of its divisors is an integer number (10500277660).

Almost surely, 2^21000555319 is an apocalyptic number.

21000555319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000555319 is an equidigital number, since it uses as much as digits as its factorization.

21000555319 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6750, while the sum is 31.

The spelling of 21000555319 in words is "twenty-one billion, five hundred fifty-five thousand, three hundred nineteen".