20626561613 has 12 divisors (see below), whose sum is σ = 24004326780. Its totient is φ = 17672421312.

The previous prime is 20626561583. The next prime is 20626561651. The reversal of 20626561613 is 31616562602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 182709289 + 20443852324 = 13517^2 + 142982^2 .

It is not a de Polignac number, because 20626561613 - 2¹² = 20626557517 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20626561013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29303 + ... + 205211.

It is an arithmetic number, because the mean of its divisors is an integer number (2000360565).

Almost surely, 2^20626561613 is an apocalyptic number.

It is an amenable number.

20626561613 is a deficient number, since it is larger than the sum of its proper divisors (3377765167).

20626561613 is a wasteful number, since it uses less digits than its factorization.

20626561613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178316 (or 178309 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The spelling of 20626561613 in words is "twenty billion, six hundred twenty-six million, five hundred sixty-one thousand, six hundred thirteen".