21543252650 has 24 divisors (see below), whose sum is σ = 40619367084. Its totient is φ = 8499254400.

The previous prime is 21543252617. The next prime is 21543252659. The reversal of 21543252650 is 5625234512.

It can be written as a sum of positive squares in 6 ways, for example, as 2361279649 + 19181973001 = 48593^2 + 138499^2 .

It is a super-2 number, since 2×21543252650² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21543252650.

It is not an unprimeable number, because it can be changed into a prime (21543252659) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2947481 + ... + 2954780.

Almost surely, 2^21543252650 is an apocalyptic number.

21543252650 is a deficient number, since it is larger than the sum of its proper divisors (19076114434).

21543252650 is a wasteful number, since it uses less digits than its factorization.

21543252650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5902346 (or 5902341 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 35.

The spelling of 21543252650 in words is "twenty-one billion, five hundred forty-three million, two hundred fifty-two thousand, six hundred fifty".