19970999 has 2 divisors, whose sum is σ = 19971000. Its totient is φ = 19970998.

The previous prime is 19970987. The next prime is 19971013. The reversal of 19970999 is 99907991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19970999 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19970999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19970959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9985499 + 9985500.

It is an arithmetic number, because the mean of its divisors is an integer number (9985500).

Almost surely, 2^19970999 is an apocalyptic number.

19970999 is a deficient number, since it is larger than the sum of its proper divisors (1).

19970999 is an equidigital number, since it uses as much as digits as its factorization.

19970999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 413343, while the sum is 53.

The square root of 19970999 is about 4468.8923683615. The cubic root of 19970999 is about 271.3104968167.

The spelling of 19970999 in words is "nineteen million, nine hundred seventy thousand, nine hundred ninety-nine".