66620559 has 4 divisors (see below), whose sum is σ = 88827416. Its totient is φ = 44413704.

The previous prime is 66620551. The next prime is 66620563. The reversal of 66620559 is 95502666.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66620559 - 2³ = 66620551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66620551) 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, 11103424 + ... + 11103429.

It is an arithmetic number, because the mean of its divisors is an integer number (22206854).

Almost surely, 2^66620559 is an apocalyptic number.

66620559 is a deficient number, since it is larger than the sum of its proper divisors (22206857).

66620559 is a wasteful number, since it uses less digits than its factorization.

66620559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22206856.

The product of its (nonzero) digits is 97200, while the sum is 39.

The square root of 66620559 is about 8162.1418144994. The cubic root of 66620559 is about 405.3866327654.

The spelling of 66620559 in words is "sixty-six million, six hundred twenty thousand, five hundred fifty-nine".