19998031 has 2 divisors, whose sum is σ = 19998032. Its totient is φ = 19998030.

The previous prime is 19998029. The next prime is 19998047. The reversal of 19998031 is 13089991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19998031 - 2¹ = 19998029 is a prime.

It is a super-2 number, since 2×19998031² = 799842487753922, which contains 22 as substring.

Together with 19998029, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19990031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9999015 + 9999016.

It is an arithmetic number, because the mean of its divisors is an integer number (9999016).

Almost surely, 2^19998031 is an apocalyptic number.

19998031 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998031 is an equidigital number, since it uses as much as digits as its factorization.

19998031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 19998031 is about 4471.9158086887. The cubic root of 19998031 is about 271.4328535533.

The spelling of 19998031 in words is "nineteen million, nine hundred ninety-eight thousand, thirty-one".