19957000997 has 2 divisors, whose sum is σ = 19957000998. Its totient is φ = 19957000996.

The previous prime is 19957000981. The next prime is 19957001023. The reversal of 19957000997 is 79900075991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17116750561 + 2840250436 = 130831^2 + 53294^2 .

It is a cyclic number.

It is not a de Polignac number, because 19957000997 - 2⁴ = 19957000981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19957000907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9978500498 + 9978500499.

It is an arithmetic number, because the mean of its divisors is an integer number (9978500499).

Almost surely, 2^19957000997 is an apocalyptic number.

It is an amenable number.

19957000997 is a deficient number, since it is larger than the sum of its proper divisors (1).

19957000997 is an equidigital number, since it uses as much as digits as its factorization.

19957000997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1607445, while the sum is 56.

The spelling of 19957000997 in words is "nineteen billion, nine hundred fifty-seven million, nine hundred ninety-seven", and thus it is an aban number.