646084440 has 48 divisors (see below), whose sum is σ = 2099775600. Its totient is φ = 172289088.

The previous prime is 646084429. The next prime is 646084441. The reversal of 646084440 is 44480646.

646084440 is a `hidden beast` number, since 6 + 4 + 608 + 4 + 4 + 40 = 666.

It is a super-2 number, since 2×646084440² = 834850207220227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 646084395 and 646084404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646084441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 896980 + ... + 897699.

It is an arithmetic number, because the mean of its divisors is an integer number (43745325).

Almost surely, 2^646084440 is an apocalyptic number.

646084440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646084440 is an abundant number, since it is smaller than the sum of its proper divisors (1453691160).

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

646084440 is a wasteful number, since it uses less digits than its factorization.

646084440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794696 (or 1794689 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

The square root of 646084440 is about 25418.1911236815. The cubic root of 646084440 is about 864.4962105904.

The spelling of 646084440 in words is "six hundred forty-six million, eighty-four thousand, four hundred forty".