3991420813 has 2 divisors, whose sum is σ = 3991420814. Its totient is φ = 3991420812.

The previous prime is 3991420799. The next prime is 3991420847. The reversal of 3991420813 is 3180241993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3363768004 + 627652809 = 57998^2 + 25053^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3991420813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3991420613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995710406 + 1995710407.

It is an arithmetic number, because the mean of its divisors is an integer number (1995710407).

Almost surely, 2^3991420813 is an apocalyptic number.

It is an amenable number.

3991420813 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991420813 is an equidigital number, since it uses as much as digits as its factorization.

3991420813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 3991420813 is about 63177.6923684302. The cubic root of 3991420813 is about 1586.2653554290.

The spelling of 3991420813 in words is "three billion, nine hundred ninety-one million, four hundred twenty thousand, eight hundred thirteen".