66551747 has 2 divisors, whose sum is σ = 66551748. Its totient is φ = 66551746.

The previous prime is 66551741. The next prime is 66551777. The reversal of 66551747 is 74715566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66551747 - 2⁴ = 66551731 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66551741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33275873 + 33275874.

It is an arithmetic number, because the mean of its divisors is an integer number (33275874).

Almost surely, 2^66551747 is an apocalyptic number.

66551747 is a deficient number, since it is larger than the sum of its proper divisors (1).

66551747 is an equidigital number, since it uses as much as digits as its factorization.

66551747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 176400, while the sum is 41.

The square root of 66551747 is about 8157.9254102989. The cubic root of 66551747 is about 405.2470108266.

The spelling of 66551747 in words is "sixty-six million, five hundred fifty-one thousand, seven hundred forty-seven".