6398981 has 2 divisors, whose sum is σ = 6398982. Its totient is φ = 6398980.

The previous prime is 6398941. The next prime is 6398983. The reversal of 6398981 is 1898936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5597956 + 801025 = 2366^2 + 895^2 .

It is a cyclic number.

It is not a de Polignac number, because 6398981 - 2¹⁰ = 6397957 is a prime.

It is a super-2 number, since 2×6398981² = 81893915676722, which contains 22 as substring.

Together with 6398983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6398983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3199490 + 3199491.

It is an arithmetic number, because the mean of its divisors is an integer number (3199491).

Almost surely, 2^6398981 is an apocalyptic number.

It is an amenable number.

6398981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6398981 is an equidigital number, since it uses as much as digits as its factorization.

6398981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 44.

The square root of 6398981 is about 2529.6207225590. The cubic root of 6398981 is about 185.6536991152.

The spelling of 6398981 in words is "six million, three hundred ninety-eight thousand, nine hundred eighty-one".