64442040 has 128 divisors (see below), whose sum is σ = 210772800. Its totient is φ = 15667200.

The previous prime is 64442039. The next prime is 64442041. The reversal of 64442040 is 4024446.

It is an interprime number because it is at equal distance from previous prime (64442039) and next prime (64442041).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 64442040.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64442041) 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, 157356 + ... + 157764.

Almost surely, 2^64442040 is an apocalyptic number.

64442040 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 64442040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105386400).

64442040 is an abundant number, since it is smaller than the sum of its proper divisors (146330760).

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

64442040 is a wasteful number, since it uses less digits than its factorization.

64442040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537 (or 533 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 64442040 is about 8027.5799591159. The cubic root of 64442040 is about 400.9188045462.

Adding to 64442040 its reverse (4024446), we get a palindrome (68466486).

The spelling of 64442040 in words is "sixty-four million, four hundred forty-two thousand, forty".