9821809131 has 4 divisors (see below), whose sum is σ = 13095745512. Its totient is φ = 6547872752.

The previous prime is 9821809121. The next prime is 9821809133. The reversal of 9821809131 is 1319081289.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9821809131 - 2¹⁷ = 9821678059 is a prime.

It is a super-2 number, since 2×9821809131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9821809133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1636968186 + ... + 1636968191.

It is an arithmetic number, because the mean of its divisors is an integer number (3273936378).

Almost surely, 2^9821809131 is an apocalyptic number.

9821809131 is a deficient number, since it is larger than the sum of its proper divisors (3273936381).

9821809131 is a wasteful number, since it uses less digits than its factorization.

9821809131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3273936380.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 9821809131 is about 99105.0408960109. The cubic root of 9821809131 is about 2141.5612337875.

The spelling of 9821809131 in words is "nine billion, eight hundred twenty-one million, eight hundred nine thousand, one hundred thirty-one".