66505240 has 16 divisors (see below), whose sum is σ = 149636880. Its totient is φ = 26602080.

The previous prime is 66505217. The next prime is 66505249. The reversal of 66505240 is 4250566.

It is a junction number, because it is equal to n+sod(n) for n = 66505199 and 66505208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66505249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831276 + ... + 831355.

It is an arithmetic number, because the mean of its divisors is an integer number (9352305).

Almost surely, 2^66505240 is an apocalyptic number.

It is an amenable number.

66505240 is an abundant number, since it is smaller than the sum of its proper divisors (83131640).

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

66505240 is a wasteful number, since it uses less digits than its factorization.

66505240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662642 (or 1662638 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 66505240 is about 8155.0744938351. The cubic root of 66505240 is about 405.1525919951.

The spelling of 66505240 in words is "sixty-six million, five hundred five thousand, two hundred forty".