61808640 has 112 divisors (see below), whose sum is σ = 198168768. Its totient is φ = 16449536.

The previous prime is 61808597. The next prime is 61808641. The reversal of 61808640 is 4680816.

It is not an unprimeable number, because it can be changed into a prime (61808641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122629 + ... + 123131.

It is an arithmetic number, because the mean of its divisors is an integer number (1769364).

Almost surely, 2^61808640 is an apocalyptic number.

61808640 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 61808640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99084384).

61808640 is an abundant number, since it is smaller than the sum of its proper divisors (136360128).

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

61808640 is an equidigital number, since it uses as much as digits as its factorization.

61808640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 61808640 is about 7861.8471112074. The cubic root of 61808640 is about 395.3815466212.

The spelling of 61808640 in words is "sixty-one million, eight hundred eight thousand, six hundred forty".