2001997889 has 2 divisors, whose sum is σ = 2001997890. Its totient is φ = 2001997888.

The previous prime is 2001997883. The next prime is 2001997969. The reversal of 2001997889 is 9887991002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1989160000 + 12837889 = 44600^2 + 3583^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001997889 - 2¹² = 2001993793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2001997889.

It is not a weakly prime, because it can be changed into another prime (2001997883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000998944 + 1000998945.

It is an arithmetic number, because the mean of its divisors is an integer number (1000998945).

Almost surely, 2^2001997889 is an apocalyptic number.

It is an amenable number.

2001997889 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001997889 is an equidigital number, since it uses as much as digits as its factorization.

2001997889 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 53.

The square root of 2001997889 is about 44743.6910524825. The cubic root of 2001997889 is about 1260.3404406776.

The spelling of 2001997889 in words is "two billion, one million, nine hundred ninety-seven thousand, eight hundred eighty-nine".