66623428 has 12 divisors (see below), whose sum is σ = 117101740. Its totient is φ = 33165792.

The previous prime is 66623363. The next prime is 66623429. The reversal of 66623428 is 82432666.

It can be written as a sum of positive squares in 2 ways, for example, as 61748164 + 4875264 = 7858^2 + 2208^2 .

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66623429) 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, 35451 + ... + 37282.

Almost surely, 2^66623428 is an apocalyptic number.

It is an amenable number.

66623428 is a deficient number, since it is larger than the sum of its proper divisors (50478312).

66623428 is a wasteful number, since it uses less digits than its factorization.

66623428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72966 (or 72964 counting only the distinct ones).

The product of its digits is 82944, while the sum is 37.

The square root of 66623428 is about 8162.3175630454. The cubic root of 66623428 is about 405.3924519779.

The spelling of 66623428 in words is "sixty-six million, six hundred twenty-three thousand, four hundred twenty-eight".