64751440 has 80 divisors (see below), whose sum is σ = 169239168. Its totient is φ = 22860288.

The previous prime is 64751437. The next prime is 64751441. The reversal of 64751440 is 4415746.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64751441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22567 + ... + 25273.

Almost surely, 2^64751440 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 64751440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84619584).

64751440 is an abundant number, since it is smaller than the sum of its proper divisors (104487728).

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

64751440 is a wasteful number, since it uses less digits than its factorization.

64751440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2756 (or 2750 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 64751440 is about 8046.8279464644. The cubic root of 64751440 is about 401.5594126800.

The spelling of 64751440 in words is "sixty-four million, seven hundred fifty-one thousand, four hundred forty".