1999950061 has 4 divisors (see below), whose sum is σ = 2022421500. Its totient is φ = 1977478624.

The previous prime is 1999950047. The next prime is 1999950077. The reversal of 1999950061 is 1600599991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1600599991 = 3049 ⋅524959.

It can be written as a sum of positive squares in 2 ways, for example, as 461820100 + 1538129961 = 21490^2 + 39219^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999950061 - 2²⁷ = 1865732333 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1999949987 and 1999950014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999950361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11235586 + ... + 11235763.

It is an arithmetic number, because the mean of its divisors is an integer number (505605375).

Almost surely, 2^1999950061 is an apocalyptic number.

It is an amenable number.

1999950061 is a deficient number, since it is larger than the sum of its proper divisors (22471439).

1999950061 is an equidigital number, since it uses as much as digits as its factorization.

1999950061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22471438.

The product of its (nonzero) digits is 196830, while the sum is 49.

The square root of 1999950061 is about 44720.8012115168. The cubic root of 1999950061 is about 1259.9105632747.

The spelling of 1999950061 in words is "one billion, nine hundred ninety-nine million, nine hundred fifty thousand, sixty-one".