21757075820884 has 6 divisors (see below), whose sum is σ = 38074882686554. Its totient is φ = 10878537910440.

The previous prime is 21757075820791. The next prime is 21757075820891. The reversal of 21757075820884 is 48802857075712.

It can be written as a sum of positive squares in only one way, i.e., 11959299401284 + 9797776419600 = 3458222^2 + 3130140^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2719634477607 + ... + 2719634477614.

Almost surely, 2^{21757075820884} is an apocalyptic number.

It is an amenable number.

21757075820884 is a deficient number, since it is larger than the sum of its proper divisors (16317806865670).

21757075820884 is a wasteful number, since it uses less digits than its factorization.

21757075820884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5439268955225 (or 5439268955223 counting only the distinct ones).

The product of its (nonzero) digits is 70246400, while the sum is 64.

The spelling of 21757075820884 in words is "twenty-one trillion, seven hundred fifty-seven billion, seventy-five million, eight hundred twenty thousand, eight hundred eighty-four".