9871921869 has 8 divisors (see below), whose sum is σ = 13168072512. Its totient is φ = 6578526240.

The previous prime is 9871921849. The next prime is 9871921889. The reversal of 9871921869 is 9681291789.

It is an interprime number because it is at equal distance from previous prime (9871921849) and next prime (9871921889).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9871921869 - 2⁸ = 9871921613 is a prime.

It is a super-2 number, since 2×9871921869² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9871921849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 680377 + ... + 694734.

It is an arithmetic number, because the mean of its divisors is an integer number (1646009064).

Almost surely, 2^9871921869 is an apocalyptic number.

It is an amenable number.

9871921869 is a deficient number, since it is larger than the sum of its proper divisors (3296150643).

9871921869 is a wasteful number, since it uses less digits than its factorization.

9871921869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377507.

The product of its digits is 3919104, while the sum is 60.

The square root of 9871921869 is about 99357.5456067631. The cubic root of 9871921869 is about 2145.1972744160.

The spelling of 9871921869 in words is "nine billion, eight hundred seventy-one million, nine hundred twenty-one thousand, eight hundred sixty-nine".