66628537 has 4 divisors (see below), whose sum is σ = 67275520. Its totient is φ = 65981556.

The previous prime is 66628519. The next prime is 66628553. The reversal of 66628537 is 73582666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66628537 - 2¹¹ = 66626489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66628493 and 66628502.

It is not an unprimeable number, because it can be changed into a prime (66628937) 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, 323337 + ... + 323542.

It is an arithmetic number, because the mean of its divisors is an integer number (16818880).

Almost surely, 2^66628537 is an apocalyptic number.

It is an amenable number.

66628537 is a deficient number, since it is larger than the sum of its proper divisors (646983).

66628537 is a wasteful number, since it uses less digits than its factorization.

66628537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646982.

The product of its digits is 362880, while the sum is 43.

The square root of 66628537 is about 8162.6305196303. The cubic root of 66628537 is about 405.4028141841.

The spelling of 66628537 in words is "sixty-six million, six hundred twenty-eight thousand, five hundred thirty-seven".