20011989449 has 4 divisors (see below), whose sum is σ = 20101729536. Its totient is φ = 19922249364.

The previous prime is 20011989443. The next prime is 20011989451. The reversal of 20011989449 is 94498911002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011989449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20011989443) 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, 44869709 + ... + 44870154.

It is an arithmetic number, because the mean of its divisors is an integer number (5025432384).

Almost surely, 2^20011989449 is an apocalyptic number.

It is an amenable number.

20011989449 is a deficient number, since it is larger than the sum of its proper divisors (89740087).

20011989449 is an equidigital number, since it uses as much as digits as its factorization.

20011989449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89740086.

The product of its (nonzero) digits is 186624, while the sum is 47.

The spelling of 20011989449 in words is "twenty billion, eleven million, nine hundred eighty-nine thousand, four hundred forty-nine".