9821378831 has 4 divisors (see below), whose sum is σ = 10714231464. Its totient is φ = 8928526200.

The previous prime is 9821378813. The next prime is 9821378849. The reversal of 9821378831 is 1388731289.

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

It is an interprime number because it is at equal distance from previous prime (9821378813) and next prime (9821378849).

It is not a de Polignac number, because 9821378831 - 2¹⁰ = 9821377807 is a prime.

It is a super-2 number, since 2×9821378831² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9821378831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9821375831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446426300 + ... + 446426321.

It is an arithmetic number, because the mean of its divisors is an integer number (2678557866).

Almost surely, 2^9821378831 is an apocalyptic number.

9821378831 is a deficient number, since it is larger than the sum of its proper divisors (892852633).

9821378831 is a wasteful number, since it uses less digits than its factorization.

9821378831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892852632.

The product of its digits is 580608, while the sum is 50.

The square root of 9821378831 is about 99102.8699433069. The cubic root of 9821378831 is about 2141.5299589227.

The spelling of 9821378831 in words is "nine billion, eight hundred twenty-one million, three hundred seventy-eight thousand, eight hundred thirty-one".