1999064161 has 4 divisors (see below), whose sum is σ = 1999185300. Its totient is φ = 1998943024.

The previous prime is 1999064147. The next prime is 1999064219. The reversal of 1999064161 is 1614609991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1614609991 = 107 ⋅15089813.

It can be written as a sum of positive squares in 2 ways, for example, as 1327217761 + 671846400 = 36431^2 + 25920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999064161 - 2¹³ = 1999055969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999064261) 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, 31006 + ... + 70423.

It is an arithmetic number, because the mean of its divisors is an integer number (499796325).

Almost surely, 2^1999064161 is an apocalyptic number.

It is an amenable number.

1999064161 is a deficient number, since it is larger than the sum of its proper divisors (121139).

1999064161 is a wasteful number, since it uses less digits than its factorization.

1999064161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121138.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 1999064161 is about 44710.8953276492. The cubic root of 1999064161 is about 1259.7245053601.

The spelling of 1999064161 in words is "one billion, nine hundred ninety-nine million, sixty-four thousand, one hundred sixty-one".