9871278388 has 12 divisors (see below), whose sum is σ = 17279284932. Its totient is φ = 4934339840.

The previous prime is 9871278337. The next prime is 9871278397. The reversal of 9871278388 is 8838721789.

It can be written as a sum of positive squares in 2 ways, for example, as 8188802064 + 1682476324 = 90492^2 + 41018^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 307645 + ... + 338212.

It is an arithmetic number, because the mean of its divisors is an integer number (1439940411).

Almost surely, 2^9871278388 is an apocalyptic number.

It is an amenable number.

9871278388 is a deficient number, since it is larger than the sum of its proper divisors (7408006544).

9871278388 is a wasteful number, since it uses less digits than its factorization.

9871278388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649682 (or 649680 counting only the distinct ones).

The product of its digits is 10838016, while the sum is 61.

The square root of 9871278388 is about 99354.3073449762. The cubic root of 9871278388 is about 2145.1506633070.

The spelling of 9871278388 in words is "nine billion, eight hundred seventy-one million, two hundred seventy-eight thousand, three hundred eighty-eight".