21312004134 has 16 divisors (see below), whose sum is σ = 45131303088. Its totient is φ = 6686118912.

The previous prime is 21312004121. The next prime is 21312004223. The reversal of 21312004134 is 43140021312.

It is a self number, because there is not a number n which added to its sum of digits gives 21312004134.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104470507 + ... + 104470710.

It is an arithmetic number, because the mean of its divisors is an integer number (2820706443).

Almost surely, 2^21312004134 is an apocalyptic number.

21312004134 is an abundant number, since it is smaller than the sum of its proper divisors (23819298954).

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

21312004134 is a wasteful number, since it uses less digits than its factorization.

21312004134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208941239.

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

Adding to 21312004134 its reverse (43140021312), we get a palindrome (64452025446).

The spelling of 21312004134 in words is "twenty-one billion, three hundred twelve million, four thousand, one hundred thirty-four".