63998531 has 2 divisors, whose sum is σ = 63998532. Its totient is φ = 63998530.

The previous prime is 63998497. The next prime is 63998533. The reversal of 63998531 is 13589936.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63998531 is a prime.

It is a super-2 number, since 2×63998531² = 8191623940315922, which contains 22 as substring.

Together with 63998533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (63998533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31999265 + 31999266.

It is an arithmetic number, because the mean of its divisors is an integer number (31999266).

Almost surely, 2^63998531 is an apocalyptic number.

63998531 is a deficient number, since it is larger than the sum of its proper divisors (1).

63998531 is an equidigital number, since it uses as much as digits as its factorization.

63998531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 174960, while the sum is 44.

The square root of 63998531 is about 7999.9081869731. The cubic root of 63998531 is about 399.9969395599.

The spelling of 63998531 in words is "sixty-three million, nine hundred ninety-eight thousand, five hundred thirty-one".