21300055 has 12 divisors (see below), whose sum is σ = 29733480. Its totient is φ = 14605584.

The previous prime is 21300029. The next prime is 21300061. The reversal of 21300055 is 55000312.

It is not a de Polignac number, because 21300055 - 2¹⁹ = 20775767 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43225 + ... + 43714.

It is an arithmetic number, because the mean of its divisors is an integer number (2477790).

Almost surely, 2^21300055 is an apocalyptic number.

21300055 is a deficient number, since it is larger than the sum of its proper divisors (8433425).

21300055 is an equidigital number, since it uses as much as digits as its factorization.

21300055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86958 (or 86951 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 16.

The square root of 21300055 is about 4615.1982622635. The cubic root of 21300055 is about 277.2002227662.

Adding to 21300055 its reverse (55000312), we get a palindrome (76300367).

The spelling of 21300055 in words is "twenty-one million, three hundred thousand, fifty-five".