61659840 has 112 divisors (see below), whose sum is σ = 213603840. Its totient is φ = 14945280.

The previous prime is 61659839. The next prime is 61659863. The reversal of 61659840 is 4895616.

61659840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 7641 + ... + 13479.

Almost surely, 2^61659840 is an apocalyptic number.

61659840 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 61659840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106801920).

61659840 is an abundant number, since it is smaller than the sum of its proper divisors (151944000).

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

61659840 is a wasteful number, since it uses less digits than its factorization.

61659840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5870 (or 5860 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 61659840 is about 7852.3779837703. The cubic root of 61659840 is about 395.0640071461.

The spelling of 61659840 in words is "sixty-one million, six hundred fifty-nine thousand, eight hundred forty".