21643670532 has 24 divisors (see below), whose sum is σ = 55092979872. Its totient is φ = 6558688000.

The previous prime is 21643670497. The next prime is 21643670533. The reversal of 21643670532 is 23507634612.

It is a super-3 number, since 3×21643670532³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21643670533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81983469 + ... + 81983732.

It is an arithmetic number, because the mean of its divisors is an integer number (2295540828).

Almost surely, 2^21643670532 is an apocalyptic number.

21643670532 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21643670532 is an abundant number, since it is smaller than the sum of its proper divisors (33449309340).

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

21643670532 is a wasteful number, since it uses less digits than its factorization.

21643670532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163967219 (or 163967217 counting only the distinct ones).

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

The spelling of 21643670532 in words is "twenty-one billion, six hundred forty-three million, six hundred seventy thousand, five hundred thirty-two".