6421766478 has 16 divisors (see below), whose sum is σ = 12871278336. Its totient is φ = 2135964600.

The previous prime is 6421766453. The next prime is 6421766489. The reversal of 6421766478 is 8746671246.

It is a self number, because there is not a number n which added to its sum of digits gives 6421766478.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1153048 + ... + 1158603.

It is an arithmetic number, because the mean of its divisors is an integer number (804454896).

Almost surely, 2^6421766478 is an apocalyptic number.

6421766478 is an abundant number, since it is smaller than the sum of its proper divisors (6449511858).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6421766478 is a wasteful number, since it uses less digits than its factorization.

6421766478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2312119.

The product of its digits is 2709504, while the sum is 51.

The square root of 6421766478 is about 80135.9250149395. The cubic root of 6421766478 is about 1858.7379651372.

The spelling of 6421766478 in words is "six billion, four hundred twenty-one million, seven hundred sixty-six thousand, four hundred seventy-eight".