1999619901 has 6 divisors (see below), whose sum is σ = 2888339870. Its totient is φ = 1333079928.

The previous prime is 1999619899. The next prime is 1999619957. The reversal of 1999619901 is 1099169991.

1999619901 is a `hidden beast` number, since 19 + 9 + 9 + 619 + 9 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1859765625 + 139854276 = 43125^2 + 11826^2 .

It is not a de Polignac number, because 1999619901 - 2¹ = 1999619899 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999619801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 111089986 + ... + 111090003.

Almost surely, 2^1999619901 is an apocalyptic number.

It is an amenable number.

1999619901 is a deficient number, since it is larger than the sum of its proper divisors (888719969).

1999619901 is a wasteful number, since it uses less digits than its factorization.

1999619901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222179995 (or 222179992 counting only the distinct ones).

The product of its (nonzero) digits is 354294, while the sum is 54.

The square root of 1999619901 is about 44717.1097120554. The cubic root of 1999619901 is about 1259.8412290495.

The spelling of 1999619901 in words is "one billion, nine hundred ninety-nine million, six hundred nineteen thousand, nine hundred one".