618531840 has 264 divisors, whose sum is σ = 2217441408. Its totient is φ = 159252480.

The previous prime is 618531817. The next prime is 618531841. The reversal of 618531840 is 48135816.

618531840 is a `hidden beast` number, since 618 + 5 + 31 + 8 + 4 + 0 = 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 = 618531795 and 618531804.

It is not an unprimeable number, because it can be changed into a prime (618531841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1428264 + ... + 1428696.

Almost surely, 2^618531840 is an apocalyptic number.

618531840 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 618531840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1108720704).

618531840 is an abundant number, since it is smaller than the sum of its proper divisors (1598909568).

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

618531840 is a wasteful number, since it uses less digits than its factorization.

618531840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 474 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 618531840 is about 24870.3003600680. The cubic root of 618531840 is about 852.0283003229.

It can be divided in two parts, 6185 and 31840, that added together give a square (38025 = 195²).

The spelling of 618531840 in words is "six hundred eighteen million, five hundred thirty-one thousand, eight hundred forty".