66537240 has 256 divisors, whose sum is σ = 262656000. Its totient is φ = 13063680.

The previous prime is 66537239. The next prime is 66537241. The reversal of 66537240 is 4273566.

It is an interprime number because it is at equal distance from previous prime (66537239) and next prime (66537241).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66537241) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 175371 + ... + 175749.

It is an arithmetic number, because the mean of its divisors is an integer number (1026000).

Almost surely, 2^66537240 is an apocalyptic number.

66537240 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 66537240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131328000).

66537240 is an abundant number, since it is smaller than the sum of its proper divisors (196118760).

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

66537240 is a wasteful number, since it uses less digits than its factorization.

66537240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 426 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 33.

The square root of 66537240 is about 8157.0362264734. The cubic root of 66537240 is about 405.2175633371.

The spelling of 66537240 in words is "sixty-six million, five hundred thirty-seven thousand, two hundred forty".