666162157 has 4 divisors (see below), whose sum is σ = 675287740. Its totient is φ = 657036576.

The previous prime is 666162143. The next prime is 666162181. The reversal of 666162157 is 751261666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 751261666 = 2 ⋅375630833.

It can be written as a sum of positive squares in 2 ways, for example, as 389904516 + 276257641 = 19746^2 + 16621^2 .

It is a cyclic number.

It is not a de Polignac number, because 666162157 - 2²³ = 657773549 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 (666162197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4562682 + ... + 4562827.

It is an arithmetic number, because the mean of its divisors is an integer number (168821935).

Almost surely, 2^666162157 is an apocalyptic number.

It is an amenable number.

666162157 is a deficient number, since it is larger than the sum of its proper divisors (9125583).

666162157 is an equidigital number, since it uses as much as digits as its factorization.

666162157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9125582.

The product of its digits is 90720, while the sum is 40.

The square root of 666162157 is about 25810.1173379743. The cubic root of 666162157 is about 873.3600442303.

The spelling of 666162157 in words is "six hundred sixty-six million, one hundred sixty-two thousand, one hundred fifty-seven".