3991921268 has 24 divisors (see below), whose sum is σ = 7180825344. Its totient is φ = 1940349600.

The previous prime is 3991921267. The next prime is 3991921303. The reversal of 3991921268 is 8621291993.

It is a happy number.

It is a super-4 number, since 4×3991921268⁴ (a number of 40 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991921267) 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, 171233 + ... + 193143.

It is an arithmetic number, because the mean of its divisors is an integer number (299201056).

Almost surely, 2^3991921268 is an apocalyptic number.

It is an amenable number.

3991921268 is a deficient number, since it is larger than the sum of its proper divisors (3188904076).

3991921268 is a wasteful number, since it uses less digits than its factorization.

3991921268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23183 (or 23181 counting only the distinct ones).

The product of its digits is 419904, while the sum is 50.

The square root of 3991921268 is about 63181.6529381750. The cubic root of 3991921268 is about 1586.3316493871.

The spelling of 3991921268 in words is "three billion, nine hundred ninety-one million, nine hundred twenty-one thousand, two hundred sixty-eight".