66655091 has 2 divisors, whose sum is σ = 66655092. Its totient is φ = 66655090.

The previous prime is 66655067. The next prime is 66655123. The reversal of 66655091 is 19055666.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66655091 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66655991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33327545 + 33327546.

It is an arithmetic number, because the mean of its divisors is an integer number (33327546).

Almost surely, 2^66655091 is an apocalyptic number.

66655091 is a deficient number, since it is larger than the sum of its proper divisors (1).

66655091 is an equidigital number, since it uses as much as digits as its factorization.

66655091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48600, while the sum is 38.

The square root of 66655091 is about 8164.2569165846. The cubic root of 66655091 is about 405.4566631655.

The spelling of 66655091 in words is "sixty-six million, six hundred fifty-five thousand, ninety-one".