65723840 has 224 divisors, whose sum is σ = 201070464. Its totient is φ = 19906560.

The previous prime is 65723809. The next prime is 65723843. The reversal of 65723840 is 4832756.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 65723840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65723843) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1077410 + ... + 1077470.

It is an arithmetic number, because the mean of its divisors is an integer number (897636).

Almost surely, 2^65723840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65723840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100535232).

65723840 is an abundant number, since it is smaller than the sum of its proper divisors (135346624).

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

65723840 is a wasteful number, since it uses less digits than its factorization.

65723840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 65723840 is about 8107.0241149265. The cubic root of 65723840 is about 403.5595631476.

The spelling of 65723840 in words is "sixty-five million, seven hundred twenty-three thousand, eight hundred forty".