65613987840 has 288 divisors, whose sum is σ = 219243822336. Its totient is φ = 16724787200.

The previous prime is 65613987811. The next prime is 65613987977. The reversal of 65613987840 is 4878931656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45219115 + ... + 45220565.

It is an arithmetic number, because the mean of its divisors is an integer number (761263272).

Almost surely, 2^65613987840 is an apocalyptic number.

65613987840 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 65613987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109621911168).

65613987840 is an abundant number, since it is smaller than the sum of its proper divisors (153629834496).

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

65613987840 is an equidigital number, since it uses as much as digits as its factorization.

65613987840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516 (or 1484 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 57.

The spelling of 65613987840 in words is "sixty-five billion, six hundred thirteen million, nine hundred eighty-seven thousand, eight hundred forty".