66154909 has 2 divisors, whose sum is σ = 66154910. Its totient is φ = 66154908.

The previous prime is 66154867. The next prime is 66154919. The reversal of 66154909 is 90945166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37478884 + 28676025 = 6122^2 + 5355^2 .

It is a cyclic number.

It is not a de Polignac number, because 66154909 - 2⁹ = 66154397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66154919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33077454 + 33077455.

It is an arithmetic number, because the mean of its divisors is an integer number (33077455).

Almost surely, 2^66154909 is an apocalyptic number.

It is an amenable number.

66154909 is a deficient number, since it is larger than the sum of its proper divisors (1).

66154909 is an equidigital number, since it uses as much as digits as its factorization.

66154909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 66154909 is about 8133.5668067583. The cubic root of 66154909 is about 404.4399289845.

The spelling of 66154909 in words is "sixty-six million, one hundred fifty-four thousand, nine hundred nine".