21236234456 has 8 divisors (see below), whose sum is σ = 39817939620. Its totient is φ = 10618117224.

The previous prime is 21236234429. The next prime is 21236234477. The reversal of 21236234456 is 65443263212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1327264646 + ... + 1327264661.

Almost surely, 2^21236234456 is an apocalyptic number.

It is an amenable number.

21236234456 is a deficient number, since it is larger than the sum of its proper divisors (18581705164).

21236234456 is a wasteful number, since it uses less digits than its factorization.

21236234456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2654529313 (or 2654529309 counting only the distinct ones).

The product of its digits is 207360, while the sum is 38.

Adding to 21236234456 its reverse (65443263212), we get a palindrome (86679497668).

The spelling of 21236234456 in words is "twenty-one billion, two hundred thirty-six million, two hundred thirty-four thousand, four hundred fifty-six".