64445520 has 80 divisors (see below), whose sum is σ = 200737152. Its totient is φ = 17103360.

The previous prime is 64445503. The next prime is 64445531. The reversal of 64445520 is 2554446.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 62610 + ... + 63630.

Almost surely, 2^64445520 is an apocalyptic number.

64445520 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 64445520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100368576).

64445520 is an abundant number, since it is smaller than the sum of its proper divisors (136291632).

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

64445520 is a wasteful number, since it uses less digits than its factorization.

64445520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300 (or 1294 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The square root of 64445520 is about 8027.7967089358. The cubic root of 64445520 is about 400.9260212241.

Adding to 64445520 its reverse (2554446), we get a palindrome (66999966).

It can be divided in two parts, 644 and 45520, that added together give a palindrome (46164).

The spelling of 64445520 in words is "sixty-four million, four hundred forty-five thousand, five hundred twenty".