19958999 has 2 divisors, whose sum is σ = 19959000. Its totient is φ = 19958998.

The previous prime is 19958977. The next prime is 19959001. The reversal of 19958999 is 99985991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19958999 is a prime.

Together with 19959001, 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 (19958909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9979499 + 9979500.

It is an arithmetic number, because the mean of its divisors is an integer number (9979500).

Almost surely, 2^19958999 is an apocalyptic number.

19958999 is a deficient number, since it is larger than the sum of its proper divisors (1).

19958999 is an equidigital number, since it uses as much as digits as its factorization.

19958999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2361960, while the sum is 59.

The square root of 19958999 is about 4467.5495520475. The cubic root of 19958999 is about 271.2561450327.

The spelling of 19958999 in words is "nineteen million, nine hundred fifty-eight thousand, nine hundred ninety-nine".