64455840 has 144 divisors (see below), whose sum is σ = 232982568. Its totient is φ = 16171008.

The previous prime is 64455817. The next prime is 64455841. The reversal of 64455840 is 4855446.

64455840 is a `hidden beast` number, since 64 + 4 + 558 + 40 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 49617936 + 14837904 = 7044^2 + 3852^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 64455795 and 64455804.

It is not an unprimeable number, because it can be changed into a prime (64455841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23164 + ... + 25796.

Almost surely, 2^64455840 is an apocalyptic number.

64455840 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 64455840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116491284).

64455840 is an abundant number, since it is smaller than the sum of its proper divisors (168526728).

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

64455840 is a wasteful number, since it uses less digits than its factorization.

64455840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2671 (or 2660 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The square root of 64455840 is about 8028.4394498557. The cubic root of 64455840 is about 400.9474208792.

The spelling of 64455840 in words is "sixty-four million, four hundred fifty-five thousand, eight hundred forty".