6445244736 has 224 divisors, whose sum is σ = 22597140480. Its totient is φ = 1761357312.

The previous prime is 6445244683. The next prime is 6445244737. The reversal of 6445244736 is 6374425446.

It is a tau number, because it is divible by the number of its divisors (224).

It is a junction number, because it is equal to n+sod(n) for n = 6445244691 and 6445244700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6445244737) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 266625 + ... + 289791.

Almost surely, 2^6445244736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6445244736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11298570240).

6445244736 is an abundant number, since it is smaller than the sum of its proper divisors (16151895744).

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

6445244736 is a wasteful number, since it uses less digits than its factorization.

6445244736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23218 (or 23202 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 45.

The square root of 6445244736 is about 80282.2815819282. The cubic root of 6445244736 is about 1861.0004191544. Note that the first 3 decimals are identical.

The spelling of 6445244736 in words is "six billion, four hundred forty-five million, two hundred forty-four thousand, seven hundred thirty-six".