646231818240 has 612 divisors, whose sum is σ = 2368262130624. Its totient is φ = 162989604864.

The previous prime is 646231818233. The next prime is 646231818241. The reversal of 646231818240 is 42818132646.

646231818240 is a `hidden beast` number, since 6 + 4 + 623 + 1 + 8 + 18 + 2 + 4 + 0 = 666.

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 (646231818241) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1064632017 + ... + 1064632623.

Almost surely, 2^646231818240 is an apocalyptic number.

646231818240 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 646231818240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184131065312).

646231818240 is an abundant number, since it is smaller than the sum of its proper divisors (1722030312384).

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

646231818240 is an equidigital number, since it uses as much as digits as its factorization.

646231818240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The spelling of 646231818240 in words is "six hundred forty-six billion, two hundred thirty-one million, eight hundred eighteen thousand, two hundred forty".