21004312134 has 16 divisors (see below), whose sum is σ = 45240057072. Its totient is φ = 6462865248.

The previous prime is 21004312081. The next prime is 21004312159. The reversal of 21004312134 is 43121340012.

It is a super-2 number, since 2×21004312134² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21004312134.

It is a congruent number.

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, 134642949 + ... + 134643104.

It is an arithmetic number, because the mean of its divisors is an integer number (2827503567).

Almost surely, 2^21004312134 is an apocalyptic number.

21004312134 is an abundant number, since it is smaller than the sum of its proper divisors (24235744938).

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

21004312134 is a wasteful number, since it uses less digits than its factorization.

21004312134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269286071.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21004312134 its reverse (43121340012), we get a palindrome (64125652146).

The spelling of 21004312134 in words is "twenty-one billion, four million, three hundred twelve thousand, one hundred thirty-four".