66628739 has 2 divisors, whose sum is σ = 66628740. Its totient is φ = 66628738.

The previous prime is 66628733. The next prime is 66628781. The reversal of 66628739 is 93782666.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66628739 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66628693 and 66628702.

It is not a weakly prime, because it can be changed into another prime (66628733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33314369 + 33314370.

It is an arithmetic number, because the mean of its divisors is an integer number (33314370).

Almost surely, 2^66628739 is an apocalyptic number.

66628739 is a deficient number, since it is larger than the sum of its proper divisors (1).

66628739 is an equidigital number, since it uses as much as digits as its factorization.

66628739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 47.

The square root of 66628739 is about 8162.6428930831. The cubic root of 66628739 is about 405.4032238748.

The spelling of 66628739 in words is "sixty-six million, six hundred twenty-eight thousand, seven hundred thirty-nine".