646038540 has 216 divisors, whose sum is σ = 2308007520. Its totient is φ = 145829376.

The previous prime is 646038529. The next prime is 646038553. The reversal of 646038540 is 45830646.

646038540 is a `hidden beast` number, since 6 + 4 + 603 + 8 + 5 + 40 = 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 = 646038495 and 646038504.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 784569 + ... + 785391.

It is an arithmetic number, because the mean of its divisors is an integer number (10685220).

Almost surely, 2^646038540 is an apocalyptic number.

646038540 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 646038540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1154003760).

646038540 is an abundant number, since it is smaller than the sum of its proper divisors (1661968980).

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

646038540 is a wasteful number, since it uses less digits than its factorization.

646038540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 646038540 is about 25417.2882109795. The cubic root of 646038540 is about 864.4757378713.

The spelling of 646038540 in words is "six hundred forty-six million, thirty-eight thousand, five hundred forty".