646581960 has 64 divisors (see below), whose sum is σ = 2155276800. Its totient is φ = 172421568.

The previous prime is 646581953. The next prime is 646581967. The reversal of 646581960 is 69185646.

646581960 is a `hidden beast` number, since 6 + 4 + 6 + 581 + 9 + 60 = 666.

It is an interprime number because it is at equal distance from previous prime (646581953) and next prime (646581967).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (646581967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 298264 + ... + 300423.

It is an arithmetic number, because the mean of its divisors is an integer number (33676200).

Almost surely, 2^646581960 is an apocalyptic number.

646581960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646581960 is an abundant number, since it is smaller than the sum of its proper divisors (1508694840).

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

646581960 is a wasteful number, since it uses less digits than its factorization.

646581960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598707 (or 598697 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 646581960 is about 25427.9759320320. The cubic root of 646581960 is about 864.7180566187.

The spelling of 646581960 in words is "six hundred forty-six million, five hundred eighty-one thousand, nine hundred sixty".