9821972131 has 2 divisors, whose sum is σ = 9821972132. Its totient is φ = 9821972130.

The previous prime is 9821972129. The next prime is 9821972179. The reversal of 9821972131 is 1312791289.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9821972131 - 2¹ = 9821972129 is a prime.

It is a super-2 number, since 2×9821972131² (a number of 21 digits) contains 22 as substring.

Together with 9821972129, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (9821912131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4910986065 + 4910986066.

It is an arithmetic number, because the mean of its divisors is an integer number (4910986066).

Almost surely, 2^9821972131 is an apocalyptic number.

9821972131 is a deficient number, since it is larger than the sum of its proper divisors (1).

9821972131 is an equidigital number, since it uses as much as digits as its factorization.

9821972131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 43.

The square root of 9821972131 is about 99105.8632523828. The cubic root of 9821972131 is about 2141.5730806392.

The spelling of 9821972131 in words is "nine billion, eight hundred twenty-one million, nine hundred seventy-two thousand, one hundred thirty-one".