3815811997 has 2 divisors, whose sum is σ = 3815811998. Its totient is φ = 3815811996.

The previous prime is 3815811991. The next prime is 3815812019. The reversal of 3815811997 is 7991185183.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3435600996 + 380211001 = 58614^2 + 19499^2 .

It is an emirp because it is prime and its reverse (7991185183) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3815811997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3815811991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1907905998 + 1907905999.

It is an arithmetic number, because the mean of its divisors is an integer number (1907905999).

Almost surely, 2^3815811997 is an apocalyptic number.

It is an amenable number.

3815811997 is a deficient number, since it is larger than the sum of its proper divisors (1).

3815811997 is an equidigital number, since it uses as much as digits as its factorization.

3815811997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 52.

The square root of 3815811997 is about 61772.2591217126. The cubic root of 3815811997 is about 1562.6521831677.

The spelling of 3815811997 in words is "three billion, eight hundred fifteen million, eight hundred eleven thousand, nine hundred ninety-seven".