21536343652 has 12 divisors (see below), whose sum is σ = 37689637356. Its totient is φ = 10767875840.

The previous prime is 21536343623. The next prime is 21536343667. The reversal of 21536343652 is 25634363512.

It can be written as a sum of positive squares in 2 ways, for example, as 6607413796 + 14928929856 = 81286^2 + 122184^2 .

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, 215952 + ... + 299512.

It is an arithmetic number, because the mean of its divisors is an integer number (3140803113).

Almost surely, 2^21536343652 is an apocalyptic number.

It is an amenable number.

21536343652 is a deficient number, since it is larger than the sum of its proper divisors (16153293704).

21536343652 is a wasteful number, since it uses less digits than its factorization.

21536343652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147998 (or 147996 counting only the distinct ones).

The product of its digits is 388800, while the sum is 40.

The spelling of 21536343652 in words is "twenty-one billion, five hundred thirty-six million, three hundred forty-three thousand, six hundred fifty-two".