6440213940 has 48 divisors (see below), whose sum is σ = 18079746048. Its totient is φ = 1712900224.

The previous prime is 6440213933. The next prime is 6440213977. The reversal of 6440213940 is 493120446.

It is a super-3 number, since 3×6440213940³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117147 + ... + 163106.

It is an arithmetic number, because the mean of its divisors is an integer number (376661376).

Almost surely, 2^6440213940 is an apocalyptic number.

6440213940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6440213940 is an abundant number, since it is smaller than the sum of its proper divisors (11639532108).

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

6440213940 is a wasteful number, since it uses less digits than its factorization.

6440213940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280648 (or 280646 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 6440213940 is about 80250.9435458550. The cubic root of 6440213940 is about 1860.5160956568.

The spelling of 6440213940 in words is "six billion, four hundred forty million, two hundred thirteen thousand, nine hundred forty".