21590055 has 24 divisors (see below), whose sum is σ = 38437152. Its totient is φ = 11202624.

The previous prime is 21590039. The next prime is 21590059. The reversal of 21590055 is 55009512.

21590055 is a `hidden beast` number, since 21 + 590 + 0 + 55 = 666.

It is not a de Polignac number, because 21590055 - 2⁴ = 21590039 is a prime.

It is a super-2 number, since 2×21590055² = 932260949806050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21590059) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 4819 + ... + 8148.

It is an arithmetic number, because the mean of its divisors is an integer number (1601548).

Almost surely, 2^21590055 is an apocalyptic number.

21590055 is a deficient number, since it is larger than the sum of its proper divisors (16847097).

21590055 is a wasteful number, since it uses less digits than its factorization.

21590055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13015 (or 13012 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 21590055 is about 4646.5099806199. The cubic root of 21590055 is about 278.4525821583.

Adding to 21590055 its reverse (55009512), we get a palindrome (76599567).

The spelling of 21590055 in words is "twenty-one million, five hundred ninety thousand, fifty-five".