20170620557 has 4 divisors (see below), whose sum is σ = 20639704800. Its totient is φ = 19701536316.

The previous prime is 20170620551. The next prime is 20170620563. The reversal of 20170620557 is 75502607102.

It is a happy number.

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 an interprime number because it is at equal distance from previous prime (20170620551) and next prime (20170620563).

It is a cyclic number.

It is not a de Polignac number, because 20170620557 - 2⁴ = 20170620541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20170620551) 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 3 ways as a sum of consecutive naturals, for example, 234542057 + ... + 234542142.

It is an arithmetic number, because the mean of its divisors is an integer number (5159926200).

Almost surely, 2^20170620557 is an apocalyptic number.

It is an amenable number.

20170620557 is a deficient number, since it is larger than the sum of its proper divisors (469084243).

20170620557 is an equidigital number, since it uses as much as digits as its factorization.

20170620557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469084242.

The product of its (nonzero) digits is 29400, while the sum is 35.

The spelling of 20170620557 in words is "twenty billion, one hundred seventy million, six hundred twenty thousand, five hundred fifty-seven".