21255000005 has 16 divisors (see below), whose sum is σ = 26634182400. Its totient is φ = 16252946688.

The previous prime is 21254999993. The next prime is 21255000017. The reversal of 21255000005 is 50000055212.

It is an interprime number because it is at equal distance from previous prime (21254999993) and next prime (21255000017).

It is not a de Polignac number, because 21255000005 - 2¹⁶ = 21254934469 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94829 + ... + 226941.

It is an arithmetic number, because the mean of its divisors is an integer number (1664636400).

Almost surely, 2^21255000005 is an apocalyptic number.

It is an amenable number.

21255000005 is a deficient number, since it is larger than the sum of its proper divisors (5379182395).

21255000005 is a wasteful number, since it uses less digits than its factorization.

21255000005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133540.

The product of its (nonzero) digits is 500, while the sum is 20.

Adding to 21255000005 its reverse (50000055212), we get a palindrome (71255055217).

The spelling of 21255000005 in words is "twenty-one billion, two hundred fifty-five million, five", and thus it is an aban number.