21400520064471 has 12 divisors (see below), whose sum is σ = 30993423962280. Its totient is φ = 14229369539280.

The previous prime is 21400520064437. The next prime is 21400520064503. The reversal of 21400520064471 is 17446002500412.

21400520064471 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 0 + 5 + 2 + 0 + 0 + 644 + 7 + 1 = 666.

It is not a de Polignac number, because 21400520064471 - 2¹⁵ = 21400520031703 is a prime.

It is a super-3 number, since 3×21400520064471³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400520064971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3136982820 + ... + 3136989641.

It is an arithmetic number, because the mean of its divisors is an integer number (2582785330190).

Almost surely, 2^{21400520064471} is an apocalyptic number.

21400520064471 is a deficient number, since it is larger than the sum of its proper divisors (9592903897809).

21400520064471 is a wasteful number, since it uses less digits than its factorization.

21400520064471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6273972846 (or 6273972843 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

Adding to 21400520064471 its reverse (17446002500412), we get a palindrome (38846522564883).

The spelling of 21400520064471 in words is "twenty-one trillion, four hundred billion, five hundred twenty million, sixty-four thousand, four hundred seventy-one".