21137785857793 has 32 divisors (see below), whose sum is σ = 24530644224000. Its totient is φ = 18011854008000.

The previous prime is 21137785857791. The next prime is 21137785857809. The reversal of 21137785857793 is 39775858773112.

It is a cyclic number.

It is not a de Polignac number, because 21137785857793 - 2¹ = 21137785857791 is a prime.

It is a super-3 number, since 3×21137785857793³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21137785857791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29686258 + ... + 30389956.

It is an arithmetic number, because the mean of its divisors is an integer number (766582632000).

Almost surely, 2^{21137785857793} is an apocalyptic number.

It is an amenable number.

21137785857793 is a deficient number, since it is larger than the sum of its proper divisors (3392858366207).

21137785857793 is a wasteful number, since it uses less digits than its factorization.

21137785857793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705253.

The product of its digits is 622339200, while the sum is 73.

The spelling of 21137785857793 in words is "twenty-one trillion, one hundred thirty-seven billion, seven hundred eighty-five million, eight hundred fifty-seven thousand, seven hundred ninety-three".