3991996037971 has 8 divisors (see below), whose sum is σ = 4121487816704. Its totient is φ = 3862549116360.

The previous prime is 3991996037969. The next prime is 3991996038029. The reversal of 3991996037971 is 1797306991993.

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 3991996037971 - 2¹ = 3991996037969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3991996037894 and 3991996037903.

It is not an unprimeable number, because it can be changed into a prime (3991996007971) 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, 11033361 + ... + 11389426.

It is an arithmetic number, because the mean of its divisors is an integer number (515185977088).

Almost surely, 2^{3991996037971} is an apocalyptic number.

3991996037971 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

3991996037971 is a deficient number, since it is larger than the sum of its proper divisors (129491778733).

3991996037971 is a wasteful number, since it uses less digits than its factorization.

3991996037971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22428561.

The product of its (nonzero) digits is 156243654, while the sum is 73.

The spelling of 3991996037971 in words is "three trillion, nine hundred ninety-one billion, nine hundred ninety-six million, thirty-seven thousand, nine hundred seventy-one".