21445263652 has 12 divisors (see below), whose sum is σ = 37768252060. Its totient is φ = 10654334496.

The previous prime is 21445263613. The next prime is 21445263661. The reversal of 21445263652 is 25636254412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12610391616 + 8834872036 = 112296^2 + 93994^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17073627 + ... + 17074882.

Almost surely, 2^21445263652 is an apocalyptic number.

It is an amenable number.

21445263652 is a deficient number, since it is larger than the sum of its proper divisors (16322988408).

21445263652 is a wasteful number, since it uses less digits than its factorization.

21445263652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34148670 (or 34148668 counting only the distinct ones).

The product of its digits is 345600, while the sum is 40.

The spelling of 21445263652 in words is "twenty-one billion, four hundred forty-five million, two hundred sixty-three thousand, six hundred fifty-two".