20489221917 has 20 divisors (see below), whose sum is σ = 30888170940. Its totient is φ = 13534159104.

The previous prime is 20489221867. The next prime is 20489221931. The reversal of 20489221917 is 71912298402.

It can be written as a sum of positive squares in 2 ways, for example, as 14672719161 + 5816502756 = 121131^2 + 76266^2 .

It is not a de Polignac number, because 20489221917 - 2⁷ = 20489221789 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20489211917) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1151508 + ... + 1169165.

It is an arithmetic number, because the mean of its divisors is an integer number (1544408547).

Almost surely, 2^20489221917 is an apocalyptic number.

20489221917 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20489221917 is a deficient number, since it is larger than the sum of its proper divisors (10398949023).

20489221917 is a wasteful number, since it uses less digits than its factorization.

20489221917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2320794 (or 2320785 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 20489221917 in words is "twenty billion, four hundred eighty-nine million, two hundred twenty-one thousand, nine hundred seventeen".