3988731321 has 6 divisors (see below), whose sum is σ = 5761500810. Its totient is φ = 2659154208.

The previous prime is 3988731319. The next prime is 3988731347. The reversal of 3988731321 is 1231378893.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3935805696 + 52925625 = 62736^2 + 7275^2 .

It is not a de Polignac number, because 3988731321 - 2¹ = 3988731319 is a prime.

It is a super-2 number, since 2×3988731321² = 31819955102252810082, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (3988731391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 221596176 + ... + 221596193.

It is an arithmetic number, because the mean of its divisors is an integer number (960250135).

Almost surely, 2^3988731321 is an apocalyptic number.

It is an amenable number.

3988731321 is a deficient number, since it is larger than the sum of its proper divisors (1772769489).

3988731321 is a wasteful number, since it uses less digits than its factorization.

3988731321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443192375 (or 443192372 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 3988731321 is about 63156.4036420694. The cubic root of 3988731321 is about 1585.9089905515.

The spelling of 3988731321 in words is "three billion, nine hundred eighty-eight million, seven hundred thirty-one thousand, three hundred twenty-one".