64537440 has 192 divisors, whose sum is σ = 235146240. Its totient is φ = 14704640.

The previous prime is 64537393. The next prime is 64537469. The reversal of 64537440 is 4473546.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89401 + ... + 90119.

It is an arithmetic number, because the mean of its divisors is an integer number (1224720).

Almost surely, 2^64537440 is an apocalyptic number.

64537440 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 64537440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117573120).

64537440 is an abundant number, since it is smaller than the sum of its proper divisors (170608800).

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

64537440 is a wasteful number, since it uses less digits than its factorization.

64537440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765 (or 757 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 33.

The square root of 64537440 is about 8033.5197765363. The cubic root of 64537440 is about 401.1165470733.

The spelling of 64537440 in words is "sixty-four million, five hundred thirty-seven thousand, four hundred forty".