6445818894 has 24 divisors (see below), whose sum is σ = 13605860520. Its totient is φ = 2035521072.

The previous prime is 6445818781. The next prime is 6445818941. The reversal of 6445818894 is 4988185446.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1485789 + ... + 1490120.

It is an arithmetic number, because the mean of its divisors is an integer number (566910855).

Almost surely, 2^6445818894 is an apocalyptic number.

6445818894 is an abundant number, since it is smaller than the sum of its proper divisors (7160041626).

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

6445818894 is a wasteful number, since it uses less digits than its factorization.

6445818894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2975952 (or 2975933 counting only the distinct ones).

The product of its digits is 8847360, while the sum is 57.

The square root of 6445818894 is about 80285.8573722670. The cubic root of 6445818894 is about 1861.0556783207.

The spelling of 6445818894 in words is "six billion, four hundred forty-five million, eight hundred eighteen thousand, eight hundred ninety-four".