19990031 has 2 divisors, whose sum is σ = 19990032. Its totient is φ = 19990030.

The previous prime is 19989997. The next prime is 19990043. The reversal of 19990031 is 13009991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19990031 - 2¹⁸ = 19727887 is a prime.

It is a super-2 number, since 2×19990031² = 799202678761922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19990031.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19990931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9995015 + 9995016.

It is an arithmetic number, because the mean of its divisors is an integer number (9995016).

Almost surely, 2^19990031 is an apocalyptic number.

19990031 is a deficient number, since it is larger than the sum of its proper divisors (1).

19990031 is an equidigital number, since it uses as much as digits as its factorization.

19990031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 19990031 is about 4471.0212479925. The cubic root of 19990031 is about 271.3966541153.

The spelling of 19990031 in words is "nineteen million, nine hundred ninety thousand, thirty-one".