666542053 has 4 divisors (see below), whose sum is σ = 668948620. Its totient is φ = 664135488.

The previous prime is 666542033. The next prime is 666542077. The reversal of 666542053 is 350245666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 350245666 = 2 ⋅175122833.

It can be written as a sum of positive squares in 2 ways, for example, as 63250209 + 603291844 = 7953^2 + 24562^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666542053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666542033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1202868 + ... + 1203421.

It is an arithmetic number, because the mean of its divisors is an integer number (167237155).

Almost surely, 2^666542053 is an apocalyptic number.

It is an amenable number.

666542053 is a deficient number, since it is larger than the sum of its proper divisors (2406567).

666542053 is a wasteful number, since it uses less digits than its factorization.

666542053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2406566.

The product of its (nonzero) digits is 129600, while the sum is 37.

The square root of 666542053 is about 25817.4757286610. The cubic root of 666542053 is about 873.5260313122.

The spelling of 666542053 in words is "six hundred sixty-six million, five hundred forty-two thousand, fifty-three".