61335843840 has 308 divisors, whose sum is σ = 220613730084. Its totient is φ = 16355229696.

The previous prime is 61335843823. The next prime is 61335843859. The reversal of 61335843840 is 4834853316.

61335843840 is a `hidden beast` number, since 6 + 1 + 33 + 584 + 38 + 4 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 46283498496 + 15052345344 = 215136^2 + 122688^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 3724264 + ... + 3740696.

Almost surely, 2^61335843840 is an apocalyptic number.

61335843840 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 61335843840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110306865042).

61335843840 is an abundant number, since it is smaller than the sum of its proper divisors (159277886244).

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

61335843840 is an equidigital number, since it uses as much as digits as its factorization.

61335843840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16476 (or 16443 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 45.

The spelling of 61335843840 in words is "sixty-one billion, three hundred thirty-five million, eight hundred forty-three thousand, eight hundred forty".