646990080 has 432 divisors, whose sum is σ = 2439751104. Its totient is φ = 144834560.

The previous prime is 646990073. The next prime is 646990081. The reversal of 646990080 is 80099646.

It is not an unprimeable number, because it can be changed into a prime (646990081) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12207334 + ... + 12207386.

It is an arithmetic number, because the mean of its divisors is an integer number (5647572).

Almost surely, 2^646990080 is an apocalyptic number.

646990080 is a gapful number since it is divisible by the number (60) 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 646990080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1219875552).

646990080 is an abundant number, since it is smaller than the sum of its proper divisors (1792761024).

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

646990080 is a wasteful number, since it uses less digits than its factorization.

646990080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 91 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 646990080 is about 25435.9996854851. Note that the first 3 decimals coincide. The cubic root of 646990080 is about 864.8999539029.

The spelling of 646990080 in words is "six hundred forty-six million, nine hundred ninety thousand, eighty".