21247660533 has 16 divisors (see below), whose sum is σ = 30979468800. Its totient is φ = 12846628080.

The previous prime is 21247660529. The next prime is 21247660549. The reversal of 21247660533 is 33506674212.

It is not a de Polignac number, because 21247660533 - 2² = 21247660529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21247660491 and 21247660500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21247660573) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 754513 + ... + 782166.

It is an arithmetic number, because the mean of its divisors is an integer number (1936216800).

Almost surely, 2^21247660533 is an apocalyptic number.

It is an amenable number.

21247660533 is a deficient number, since it is larger than the sum of its proper divisors (9731808267).

21247660533 is a wasteful number, since it uses less digits than its factorization.

21247660533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1537112.

The product of its (nonzero) digits is 181440, while the sum is 39.

The spelling of 21247660533 in words is "twenty-one billion, two hundred forty-seven million, six hundred sixty thousand, five hundred thirty-three".