21121885317 has 32 divisors (see below), whose sum is σ = 31539271680. Its totient is φ = 12484039680.

The previous prime is 21121885283. The next prime is 21121885333. The reversal of 21121885317 is 71358812112.

It is not a de Polignac number, because 21121885317 - 2¹⁹ = 21121361029 is a prime.

It is a super-2 number, since 2×21121885317² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121885357) 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, 167133 + ... + 264909.

It is an arithmetic number, because the mean of its divisors is an integer number (985602240).

Almost surely, 2^21121885317 is an apocalyptic number.

It is an amenable number.

21121885317 is a deficient number, since it is larger than the sum of its proper divisors (10417386363).

21121885317 is a wasteful number, since it uses less digits than its factorization.

21121885317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98013.

The product of its digits is 26880, while the sum is 39.

The spelling of 21121885317 in words is "twenty-one billion, one hundred twenty-one million, eight hundred eighty-five thousand, three hundred seventeen".