646353540 has 192 divisors, whose sum is σ = 2322270720. Its totient is φ = 146188800.

The previous prime is 646353523. The next prime is 646353551. The reversal of 646353540 is 45353646.

646353540 is a `hidden beast` number, since 6 + 4 + 63 + 53 + 540 = 666.

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 = 646353495 and 646353504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 380934 + ... + 382626.

It is an arithmetic number, because the mean of its divisors is an integer number (12095160).

Almost surely, 2^646353540 is an apocalyptic number.

646353540 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 646353540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1161135360).

646353540 is an abundant number, since it is smaller than the sum of its proper divisors (1675917180).

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

646353540 is a wasteful number, since it uses less digits than its factorization.

646353540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1819 (or 1811 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 646353540 is about 25423.4840256012. The cubic root of 646353540 is about 864.6162174219.

The spelling of 646353540 in words is "six hundred forty-six million, three hundred fifty-three thousand, five hundred forty".