21705537248 has 24 divisors (see below), whose sum is σ = 43726564728. Its totient is φ = 10600377984.

The previous prime is 21705537247. The next prime is 21705537257. The reversal of 21705537248 is 84273550712.

It is a super-2 number, since 2×21705537248² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21705537199 and 21705537208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21705537241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7885811 + ... + 7888562.

It is an arithmetic number, because the mean of its divisors is an integer number (1821940197).

Almost surely, 2^21705537248 is an apocalyptic number.

It is an amenable number.

21705537248 is an abundant number, since it is smaller than the sum of its proper divisors (22021027480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21705537248 is a wasteful number, since it uses less digits than its factorization.

21705537248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15774426 (or 15774418 counting only the distinct ones).

The product of its (nonzero) digits is 470400, while the sum is 44.

The spelling of 21705537248 in words is "twenty-one billion, seven hundred five million, five hundred thirty-seven thousand, two hundred forty-eight".