21126684458 has 12 divisors (see below), whose sum is σ = 34832839650. Its totient is φ = 9603038280.

The previous prime is 21126684457. The next prime is 21126684529. The reversal of 21126684458 is 85448662112.

It can be written as a sum of positive squares in only one way, i.e., 20439563089 + 687121369 = 142967^2 + 26213^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21126684457) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43649933 + ... + 43650416.

Almost surely, 2^21126684458 is an apocalyptic number.

21126684458 is a deficient number, since it is larger than the sum of its proper divisors (13706155192).

21126684458 is a wasteful number, since it uses less digits than its factorization.

21126684458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87300373 (or 87300362 counting only the distinct ones).

The product of its digits is 737280, while the sum is 47.

The spelling of 21126684458 in words is "twenty-one billion, one hundred twenty-six million, six hundred eighty-four thousand, four hundred fifty-eight".