21711020084 has 12 divisors (see below), whose sum is σ = 40916922564. Its totient is φ = 10020470784.

The previous prime is 21711020083. The next prime is 21711020087. The reversal of 21711020084 is 48002011712.

It can be written as a sum of positive squares in 2 ways, for example, as 6436531984 + 15274488100 = 80228^2 + 123590^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21711020083) 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, 208759757 + ... + 208759860.

It is an arithmetic number, because the mean of its divisors is an integer number (3409743547).

Almost surely, 2^21711020084 is an apocalyptic number.

It is an amenable number.

21711020084 is a deficient number, since it is larger than the sum of its proper divisors (19205902480).

21711020084 is a wasteful number, since it uses less digits than its factorization.

21711020084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417519634 (or 417519632 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

Adding to 21711020084 its reverse (48002011712), we get a palindrome (69713031796).

The spelling of 21711020084 in words is "twenty-one billion, seven hundred eleven million, twenty thousand, eighty-four".