66988807 has 2 divisors, whose sum is σ = 66988808. Its totient is φ = 66988806.

The previous prime is 66988783. The next prime is 66988819. The reversal of 66988807 is 70888966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66988807 - 2¹⁵ = 66956039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66988837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33494403 + 33494404.

It is an arithmetic number, because the mean of its divisors is an integer number (33494404).

Almost surely, 2^66988807 is an apocalyptic number.

66988807 is a deficient number, since it is larger than the sum of its proper divisors (1).

66988807 is an equidigital number, since it uses as much as digits as its factorization.

66988807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1161216, while the sum is 52.

The square root of 66988807 is about 8184.6690220192. The cubic root of 66988807 is about 406.1321914179.

The spelling of 66988807 in words is "sixty-six million, nine hundred eighty-eight thousand, eight hundred seven".