66025620 has 72 divisors (see below), whose sum is σ = 212068584. Its totient is φ = 16570368.

The previous prime is 66025591. The next prime is 66025657. The reversal of 66025620 is 2652066.

66025620 is a `hidden beast` number, since 6 + 602 + 56 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 25040016 + 40985604 = 5004^2 + 6402^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7729 + ... + 13848.

It is an arithmetic number, because the mean of its divisors is an integer number (2945397).

Almost surely, 2^66025620 is an apocalyptic number.

66025620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66025620 is an abundant number, since it is smaller than the sum of its proper divisors (146042964).

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

66025620 is a wasteful number, since it uses less digits than its factorization.

66025620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21609 (or 21604 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 66025620 is about 8125.6150536436. The cubic root of 66025620 is about 404.1762864941.

Adding to 66025620 its reverse (2652066), we get a palindrome (68677686).

The spelling of 66025620 in words is "sixty-six million, twenty-five thousand, six hundred twenty".