21464643236 has 12 divisors (see below), whose sum is σ = 37837310028. Its totient is φ = 10653983232.

The previous prime is 21464643227. The next prime is 21464643247. The reversal of 21464643236 is 63234646412.

It can be written as a sum of positive squares in 2 ways, for example, as 13088732836 + 8375910400 = 114406^2 + 91520^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21464643193 and 21464643202.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19583981 + ... + 19585076.

It is an arithmetic number, because the mean of its divisors is an integer number (3153109169).

Almost surely, 2^21464643236 is an apocalyptic number.

It is an amenable number.

21464643236 is a deficient number, since it is larger than the sum of its proper divisors (16372666792).

21464643236 is a wasteful number, since it uses less digits than its factorization.

21464643236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39169198 (or 39169196 counting only the distinct ones).

The product of its digits is 497664, while the sum is 41.

The spelling of 21464643236 in words is "twenty-one billion, four hundred sixty-four million, six hundred forty-three thousand, two hundred thirty-six".