3971681281 has 8 divisors (see below), whose sum is σ = 4125918464. Its totient is φ = 3819076560.

The previous prime is 3971681267. The next prime is 3971681291. The reversal of 3971681281 is 1821861793.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 3971681281 - 2⁵ = 3971681249 is a prime.

It is a super-2 number, since 2×3971681281² = 31548504395691601922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3971681221) 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, 403155 + ... + 412888.

It is an arithmetic number, because the mean of its divisors is an integer number (515739808).

Almost surely, 2^3971681281 is an apocalyptic number.

3971681281 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

3971681281 is a deficient number, since it is larger than the sum of its proper divisors (154237183).

3971681281 is a wasteful number, since it uses less digits than its factorization.

3971681281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816231.

The product of its digits is 145152, while the sum is 46.

The square root of 3971681281 is about 63021.2764151917. The cubic root of 3971681281 is about 1583.6460796159.

The spelling of 3971681281 in words is "three billion, nine hundred seventy-one million, six hundred eighty-one thousand, two hundred eighty-one".