6442649766 has 224 divisors, whose sum is σ = 17814256128. Its totient is φ = 1704810240.

The previous prime is 6442649743. The next prime is 6442649767. The reversal of 6442649766 is 6679462446.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6442649767) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 12318381 + ... + 12318903.

Almost surely, 2^6442649766 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6442649766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8907128064).

6442649766 is an abundant number, since it is smaller than the sum of its proper divisors (11371606362).

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

6442649766 is a wasteful number, since it uses less digits than its factorization.

6442649766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638 (or 623 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 54.

The square root of 6442649766 is about 80266.1184186703. The cubic root of 6442649766 is about 1860.7506283545.

The spelling of 6442649766 in words is "six billion, four hundred forty-two million, six hundred forty-nine thousand, seven hundred sixty-six".