21136652648 has 8 divisors (see below), whose sum is σ = 39631223730. Its totient is φ = 10568326320.

The previous prime is 21136652629. The next prime is 21136652699. The reversal of 21136652648 is 84625663112.

It can be written as a sum of positive squares in only one way, i.e., 20152073764 + 984578884 = 141958^2 + 31378^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21136652599 and 21136652608.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321040783 + ... + 1321040798.

Almost surely, 2^21136652648 is an apocalyptic number.

It is an amenable number.

21136652648 is a deficient number, since it is larger than the sum of its proper divisors (18494571082).

21136652648 is a wasteful number, since it uses less digits than its factorization.

21136652648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2642081587 (or 2642081583 counting only the distinct ones).

The product of its digits is 414720, while the sum is 44.

The spelling of 21136652648 in words is "twenty-one billion, one hundred thirty-six million, six hundred fifty-two thousand, six hundred forty-eight".