666042653 has 2 divisors, whose sum is σ = 666042654. Its totient is φ = 666042652.

The previous prime is 666042577. The next prime is 666042691. The reversal of 666042653 is 356240666.

It is an a-pointer prime, because the next prime (666042691) can be obtained adding 666042653 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 532824889 + 133217764 = 23083^2 + 11542^2 .

It is a cyclic number.

It is not a de Polignac number, because 666042653 - 2¹² = 666038557 is a prime.

It is a super-2 number, since 2×666042653² = 887225631230556818, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666092653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333021326 + 333021327.

It is an arithmetic number, because the mean of its divisors is an integer number (333021327).

Almost surely, 2^666042653 is an apocalyptic number.

It is an amenable number.

666042653 is a deficient number, since it is larger than the sum of its proper divisors (1).

666042653 is an equidigital number, since it uses as much as digits as its factorization.

666042653 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 38.

The square root of 666042653 is about 25807.8021729864. The cubic root of 666042653 is about 873.3078165760.

The spelling of 666042653 in words is "six hundred sixty-six million, forty-two thousand, six hundred fifty-three".