1999996897 has 2 divisors, whose sum is σ = 1999996898.
Its totient is φ = 1999996896.
The previous prime is 1999996879. The next prime is 1999996931. The reversal of 1999996897 is 7986999991.
Together with previous prime (1999996879) it forms an Ormiston pair, because they use the same digits, order apart.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 1999788961 + 207936 = 44719^2 + 456^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1999996897 is a prime.
It is not a weakly prime, because it can be changed into another prime (1999996847) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999998448 + 999998449.
It is an arithmetic number, because the mean of its divisors is an integer number (999998449).
Almost surely, 21999996897 is an apocalyptic number.
It is an amenable number.
1999996897 is a deficient number, since it is larger than the sum of its proper divisors (1).
1999996897 is an equidigital number, since it uses as much as digits as its factorization.
1999996897 is an evil number, because the sum of its binary digits is even.
The product of its digits is 178564176, while the sum is 76.
The square root of 1999996897 is about 44721.3248573877.
The cubic root of 1999996897 is about 1259.9203983054.
The spelling of 1999996897 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-six thousand, eight hundred ninety-seven".