21310055 has 12 divisors (see below), whose sum is σ = 27691560. Its totient is φ = 15736032.

The previous prime is 21310049. The next prime is 21310057. The reversal of 21310055 is 55001312.

It is not a de Polignac number, because 21310055 - 2⁶ = 21309991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310057) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11765 + ... + 13454.

It is an arithmetic number, because the mean of its divisors is an integer number (2307630).

Almost surely, 2^21310055 is an apocalyptic number.

21310055 is a deficient number, since it is larger than the sum of its proper divisors (6381505).

21310055 is a wasteful number, since it uses less digits than its factorization.

21310055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25250 (or 25237 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 21310055 is about 4616.2815122130. The cubic root of 21310055 is about 277.2435961838.

Adding to 21310055 its reverse (55001312), we get a palindrome (76311367).

The spelling of 21310055 in words is "twenty-one million, three hundred ten thousand, fifty-five".