1999880101 has 2 divisors, whose sum is σ = 1999880102. Its totient is φ = 1999880100.

The previous prime is 1999880063. The next prime is 1999880123. The reversal of 1999880101 is 1010889991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1941724225 + 58155876 = 44065^2 + 7626^2 .

It is an emirp because it is prime and its reverse (1010889991) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1010886661 and 1666880101.

It is a cyclic number.

It is not a de Polignac number, because 1999880101 - 2¹⁷ = 1999749029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999880161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999940050 + 999940051.

It is an arithmetic number, because the mean of its divisors is an integer number (999940051).

Almost surely, 2^1999880101 is an apocalyptic number.

It is an amenable number.

1999880101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999880101 is an equidigital number, since it uses as much as digits as its factorization.

1999880101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 46.

The square root of 1999880101 is about 44720.0190183323. The cubic root of 1999880101 is about 1259.8958721794.

The spelling of 1999880101 in words is "one billion, nine hundred ninety-nine million, eight hundred eighty thousand, one hundred one".