66502420 has 12 divisors (see below), whose sum is σ = 139655124. Its totient is φ = 26600960.

The previous prime is 66502399. The next prime is 66502427. The reversal of 66502420 is 2420566.

It can be written as a sum of positive squares in 2 ways, for example, as 12362256 + 54140164 = 3516^2 + 7358^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66502427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1662541 + ... + 1662580.

It is an arithmetic number, because the mean of its divisors is an integer number (11637927).

Almost surely, 2^66502420 is an apocalyptic number.

It is an amenable number.

66502420 is an abundant number, since it is smaller than the sum of its proper divisors (73152704).

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

66502420 is a wasteful number, since it uses less digits than its factorization.

66502420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3325130 (or 3325128 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 66502420 is about 8154.9015935203. The cubic root of 66502420 is about 405.1468653964.

Adding to 66502420 its reverse (2420566), we get a palindrome (68922986).

The spelling of 66502420 in words is "sixty-six million, five hundred two thousand, four hundred twenty".