8131993 has 2 divisors, whose sum is σ = 8131994. Its totient is φ = 8131992.

The previous prime is 8131969. The next prime is 8131997. The reversal of 8131993 is 3991318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7912969 + 219024 = 2813^2 + 468^2 .

It is a cyclic number.

It is not a de Polignac number, because 8131993 - 2⁵ = 8131961 is a prime.

It is a super-2 number, since 2×8131993² = 132258620304098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8131997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4065996 + 4065997.

It is an arithmetic number, because the mean of its divisors is an integer number (4065997).

Almost surely, 2^8131993 is an apocalyptic number.

It is an amenable number.

8131993 is a deficient number, since it is larger than the sum of its proper divisors (1).

8131993 is an equidigital number, since it uses as much as digits as its factorization.

8131993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 8131993 is about 2851.6649522691. The cubic root of 8131993 is about 201.0939471552.

The spelling of 8131993 in words is "eight million, one hundred thirty-one thousand, nine hundred ninety-three".