21820845608 has 32 divisors (see below), whose sum is σ = 43468849800. Its totient is φ = 10249489152.

The previous prime is 21820845569. The next prime is 21820845643. The reversal of 21820845608 is 80654802812.

It can be written as a sum of positive squares in 4 ways, for example, as 21802884964 + 17960644 = 147658^2 + 4238^2 .

It is a super-2 number, since 2×21820845608² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1262435 + ... + 1279602.

Almost surely, 2^21820845608 is an apocalyptic number.

It is an amenable number.

21820845608 is a deficient number, since it is larger than the sum of its proper divisors (21648004192).

21820845608 is a wasteful number, since it uses less digits than its factorization.

21820845608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2542109 (or 2542105 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 44.

The spelling of 21820845608 in words is "twenty-one billion, eight hundred twenty million, eight hundred forty-five thousand, six hundred eight".