6403205556 has 72 divisors (see below), whose sum is σ = 17674701408. Its totient is φ = 1938456000.

The previous prime is 6403205537. The next prime is 6403205569. The reversal of 6403205556 is 6555023046.

It is a happy number.

6403205556 is a `hidden beast` number, since 640 + 3 + 2 + 0 + 5 + 5 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 6403205556.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 424626 + ... + 439446.

It is an arithmetic number, because the mean of its divisors is an integer number (245481964).

Almost surely, 2^6403205556 is an apocalyptic number.

6403205556 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6403205556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8837350704).

6403205556 is an abundant number, since it is smaller than the sum of its proper divisors (11271495852).

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

6403205556 is a wasteful number, since it uses less digits than its factorization.

6403205556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15933 (or 15928 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 36.

The square root of 6403205556 is about 80020.0322169393. The cubic root of 6403205556 is about 1856.9454582265.

The spelling of 6403205556 in words is "six billion, four hundred three million, two hundred five thousand, five hundred fifty-six".