6521722200021 has 16 divisors (see below), whose sum is σ = 10140675920000. Its totient is φ = 3726698399424.

The previous prime is 6521722199981. The next prime is 6521722200053. The reversal of 6521722200021 is 1200022271256.

It is not a de Polignac number, because 6521722200021 - 2¹⁵ = 6521722167253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6521722000021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3168960196 + ... + 3168962253.

It is an arithmetic number, because the mean of its divisors is an integer number (633792245000).

Almost surely, 2^{6521722200021} is an apocalyptic number.

It is an amenable number.

6521722200021 is a deficient number, since it is larger than the sum of its proper divisors (3618953719979).

6521722200021 is an equidigital number, since it uses as much as digits as its factorization.

6521722200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6337922473 (or 6337922459 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

Adding to 6521722200021 its reverse (1200022271256), we get a palindrome (7721744471277).

The spelling of 6521722200021 in words is "six trillion, five hundred twenty-one billion, seven hundred twenty-two million, two hundred thousand, twenty-one".