21157583698517 has 16 divisors (see below), whose sum is σ = 25014048013440. Its totient is φ = 17509615271232.

The previous prime is 21157583698441. The next prime is 21157583698549. The reversal of 21157583698517 is 71589638575112.

It is not a de Polignac number, because 21157583698517 - 2¹⁰ = 21157583697493 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 (21157583698577) 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, 58342718 + ... + 58704240.

It is an arithmetic number, because the mean of its divisors is an integer number (1563378000840).

Almost surely, 2^{21157583698517} is an apocalyptic number.

It is an amenable number.

21157583698517 is a deficient number, since it is larger than the sum of its proper divisors (3856464314923).

21157583698517 is a wasteful number, since it uses less digits than its factorization.

21157583698517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649852.

The product of its digits is 127008000, while the sum is 68.

The spelling of 21157583698517 in words is "twenty-one trillion, one hundred fifty-seven billion, five hundred eighty-three million, six hundred ninety-eight thousand, five hundred seventeen".