61813440 has 252 divisors, whose sum is σ = 232038144. Its totient is φ = 15095808.

The previous prime is 61813429. The next prime is 61813447. The reversal of 61813440 is 4431816.

61813440 is a `hidden beast` number, since 618 + 1 + 3 + 4 + 40 = 666.

61813440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (61813447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 486657 + ... + 486783.

Almost surely, 2^61813440 is an apocalyptic number.

61813440 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 61813440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116019072).

61813440 is an abundant number, since it is smaller than the sum of its proper divisors (170224704).

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

61813440 is a wasteful number, since it uses less digits than its factorization.

61813440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 61813440 is about 7862.1523770530. The cubic root of 61813440 is about 395.3917813408.

The spelling of 61813440 in words is "sixty-one million, eight hundred thirteen thousand, four hundred forty".