20001019985 has 4 divisors (see below), whose sum is σ = 24001223988. Its totient is φ = 16000815984.

The previous prime is 20001019963. The next prime is 20001019993. The reversal of 20001019985 is 58991010002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14121044224 + 5879975761 = 118832^2 + 76681^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001019985 - 2⁸ = 20001019729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000101994 + ... + 2000102003.

It is an arithmetic number, because the mean of its divisors is an integer number (6000305997).

Almost surely, 2^20001019985 is an apocalyptic number.

It is an amenable number.

20001019985 is a deficient number, since it is larger than the sum of its proper divisors (4000204003).

20001019985 is an equidigital number, since it uses as much as digits as its factorization.

20001019985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4000204002.

The product of its (nonzero) digits is 6480, while the sum is 35.

Adding to 20001019985 its reverse (58991010002), we get a palindrome (78992029987).

The spelling of 20001019985 in words is "twenty billion, one million, nineteen thousand, nine hundred eighty-five".