66493440 has 352 divisors, whose sum is σ = 261360960. Its totient is φ = 15925248.

The previous prime is 66493423. The next prime is 66493447. The reversal of 66493440 is 4439466.

66493440 is a `hidden beast` number, since 6 + 649 + 3 + 4 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66493395 and 66493404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66493447) 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, 1797102 + ... + 1797138.

Almost surely, 2^66493440 is an apocalyptic number.

66493440 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 66493440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130680480).

66493440 is an abundant number, since it is smaller than the sum of its proper divisors (194867520).

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

66493440 is a wasteful number, since it uses less digits than its factorization.

66493440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 66493440 is about 8154.3509858235. The cubic root of 66493440 is about 405.1286285532.

The spelling of 66493440 in words is "sixty-six million, four hundred ninety-three thousand, four hundred forty".