3998525681 has 6 divisors (see below), whose sum is σ = 4247569110. Its totient is φ = 3763318016.

The previous prime is 3998525659. The next prime is 3998525683. The reversal of 3998525681 is 1865258993.

It can be written as a sum of positive squares in 3 ways, for example, as 990990400 + 3007535281 = 31480^2 + 54841^2 .

It is not a de Polignac number, because 3998525681 - 2⁶ = 3998525617 is a prime.

It is a super-2 number, since 2×3998525681² = 31976415243233027522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3998525683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6917576 + ... + 6918153.

It is an arithmetic number, because the mean of its divisors is an integer number (707928185).

Almost surely, 2^3998525681 is an apocalyptic number.

It is an amenable number.

3998525681 is a deficient number, since it is larger than the sum of its proper divisors (249043429).

3998525681 is a wasteful number, since it uses less digits than its factorization.

3998525681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13835763 (or 13835746 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 56.

The square root of 3998525681 is about 63233.8966140787. The cubic root of 3998525681 is about 1587.2060000412.

The spelling of 3998525681 in words is "three billion, nine hundred ninety-eight million, five hundred twenty-five thousand, six hundred eighty-one".