21221057406517 has 8 divisors (see below), whose sum is σ = 22487727249216. Its totient is φ = 19956428935872.

The previous prime is 21221057406473. The next prime is 21221057406539. The reversal of 21221057406517 is 71560475012212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221057406517 - 2¹⁹ = 21221056882229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221057406547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 510321603 + ... + 510363184.

It is an arithmetic number, because the mean of its divisors is an integer number (2810965906152).

Almost surely, 2^{21221057406517} is an apocalyptic number.

It is an amenable number.

21221057406517 is a deficient number, since it is larger than the sum of its proper divisors (1266669842699).

21221057406517 is a wasteful number, since it uses less digits than its factorization.

21221057406517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020686027.

The product of its (nonzero) digits is 235200, while the sum is 43.

The spelling of 21221057406517 in words is "twenty-one trillion, two hundred twenty-one billion, fifty-seven million, four hundred six thousand, five hundred seventeen".