66207520 has 96 divisors (see below), whose sum is σ = 167949936. Its totient is φ = 24576000.

The previous prime is 66207481. The next prime is 66207521. The reversal of 66207520 is 2570266.

It can be written as a sum of positive squares in 8 ways, for example, as 61027344 + 5180176 = 7812^2 + 2276^2 .

It is not an unprimeable number, because it can be changed into a prime (66207521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 274600 + ... + 274840.

Almost surely, 2^66207520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66207520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83974968).

66207520 is an abundant number, since it is smaller than the sum of its proper divisors (101742416).

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

66207520 is a wasteful number, since it uses less digits than its factorization.

66207520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 66207520 is about 8136.8003539475. The cubic root of 66207520 is about 404.5471135272.

Adding to 66207520 its reverse (2570266), we get a palindrome (68777786).

It can be divided in two parts, 6 and 6207520, that added together give a triangular number (6207526 = T₃₅₂₃).

The spelling of 66207520 in words is "sixty-six million, two hundred seven thousand, five hundred twenty".