21255000004 has 24 divisors (see below), whose sum is σ = 42663481280. Its totient is φ = 9076396896.

The previous prime is 21254999993. The next prime is 21255000017. The reversal of 21255000004 is 40000055212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1362474 + ... + 1377985.

Almost surely, 2^21255000004 is an apocalyptic number.

It is an amenable number.

21255000004 is an abundant number, since it is smaller than the sum of its proper divisors (21408481276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21255000004 is a wasteful number, since it uses less digits than its factorization.

21255000004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2740747 (or 2740745 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

Adding to 21255000004 its reverse (40000055212), we get a palindrome (61255055216).

The spelling of 21255000004 in words is "twenty-one billion, two hundred fifty-five million, four", and thus it is an aban number.