20617405557 has 32 divisors (see below), whose sum is σ = 32048197632. Its totient is φ = 11546466624.

The previous prime is 20617405553. The next prime is 20617405577. The reversal of 20617405557 is 75550471602.

It is a happy number.

It is not a de Polignac number, because 20617405557 - 2² = 20617405553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20617405553) 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 31 ways as a sum of consecutive naturals, for example, 239988 + ... + 314370.

It is an arithmetic number, because the mean of its divisors is an integer number (1001506176).

Almost surely, 2^20617405557 is an apocalyptic number.

It is an amenable number.

20617405557 is a deficient number, since it is larger than the sum of its proper divisors (11430792075).

20617405557 is a wasteful number, since it uses less digits than its factorization.

20617405557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74657.

The product of its (nonzero) digits is 294000, while the sum is 42.

The spelling of 20617405557 in words is "twenty billion, six hundred seventeen million, four hundred five thousand, five hundred fifty-seven".