64609440 has 288 divisors, whose sum is σ = 246141504. Its totient is φ = 14192640.

The previous prime is 64609417. The next prime is 64609463. The reversal of 64609440 is 4490646.

It is an interprime number because it is at equal distance from previous prime (64609417) and next prime (64609463).

It is a super-2 number, since 2×64609440² = 8348759474227200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 964287 + ... + 964353.

It is an arithmetic number, because the mean of its divisors is an integer number (854658).

Almost surely, 2^64609440 is an apocalyptic number.

64609440 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 64609440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123070752).

64609440 is an abundant number, since it is smaller than the sum of its proper divisors (181532064).

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

64609440 is a wasteful number, since it uses less digits than its factorization.

64609440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 64609440 is about 8037.9997511819. Note that the first 3 decimals coincide. The cubic root of 64609440 is about 401.2656577192.

The spelling of 64609440 in words is "sixty-four million, six hundred nine thousand, four hundred forty".