66432240 has 240 divisors, whose sum is σ = 261144000. Its totient is φ = 15128064.

The previous prime is 66432229. The next prime is 66432241. The reversal of 66432240 is 4223466.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×66432240² = 8826485022835200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66432241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 246826 + ... + 247094.

It is an arithmetic number, because the mean of its divisors is an integer number (1088100).

Almost surely, 2^66432240 is an apocalyptic number.

66432240 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 66432240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130572000).

66432240 is an abundant number, since it is smaller than the sum of its proper divisors (194711760).

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

66432240 is a wasteful number, since it uses less digits than its factorization.

66432240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 66432240 is about 8150.5975241083. The cubic root of 66432240 is about 405.0042980797.

The spelling of 66432240 in words is "sixty-six million, four hundred thirty-two thousand, two hundred forty".