9780138871 has 2 divisors, whose sum is σ = 9780138872. Its totient is φ = 9780138870.

The previous prime is 9780138857. The next prime is 9780138877. The reversal of 9780138871 is 1788310879.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9780138871 - 2¹⁷ = 9780007799 is a prime.

It is a super-2 number, since 2×9780138871² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9780138877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4890069435 + 4890069436.

It is an arithmetic number, because the mean of its divisors is an integer number (4890069436).

Almost surely, 2^9780138871 is an apocalyptic number.

9780138871 is a deficient number, since it is larger than the sum of its proper divisors (1).

9780138871 is an equidigital number, since it uses as much as digits as its factorization.

9780138871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 677376, while the sum is 52.

The square root of 9780138871 is about 98894.5846394028. The cubic root of 9780138871 is about 2138.5283263168.

The spelling of 9780138871 in words is "nine billion, seven hundred eighty million, one hundred thirty-eight thousand, eight hundred seventy-one".