6420987559 has 4 divisors (see below), whose sum is σ = 7338271504. Its totient is φ = 5503703616.

The previous prime is 6420987553. The next prime is 6420987571. The reversal of 6420987559 is 9557890246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6420987559 - 2¹⁷ = 6420856487 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 (6420987553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 458641962 + ... + 458641975.

It is an arithmetic number, because the mean of its divisors is an integer number (1834567876).

Almost surely, 2^6420987559 is an apocalyptic number.

6420987559 is a deficient number, since it is larger than the sum of its proper divisors (917283945).

6420987559 is an equidigital number, since it uses as much as digits as its factorization.

6420987559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917283944.

The product of its (nonzero) digits is 5443200, while the sum is 55.

The square root of 6420987559 is about 80131.0648812307. The cubic root of 6420987559 is about 1858.6628111089.

The spelling of 6420987559 in words is "six billion, four hundred twenty million, nine hundred eighty-seven thousand, five hundred fifty-nine".