20420947989 has 48 divisors (see below), whose sum is σ = 33282546752. Its totient is φ = 12436996608.

The previous prime is 20420947973. The next prime is 20420947991. The reversal of 20420947989 is 98974902402.

It is not a de Polignac number, because 20420947989 - 2⁴ = 20420947973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420947909) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 273102 + ... + 339744.

Almost surely, 2^20420947989 is an apocalyptic number.

It is an amenable number.

20420947989 is a deficient number, since it is larger than the sum of its proper divisors (12861598763).

20420947989 is an equidigital number, since it uses as much as digits as its factorization.

20420947989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66768 (or 66756 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 20420947989 in words is "twenty billion, four hundred twenty million, nine hundred forty-seven thousand, nine hundred eighty-nine".