18645857 has 4 divisors (see below), whose sum is σ = 19100676. Its totient is φ = 18191040.

The previous prime is 18645841. The next prime is 18645863. The reversal of 18645857 is 75854681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75854681 = 7 ⋅10836383.

It can be written as a sum of positive squares in 2 ways, for example, as 6507601 + 12138256 = 2551^2 + 3484^2 .

It is a cyclic number.

It is not a de Polignac number, because 18645857 - 2⁴ = 18645841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18645457) 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, 227348 + ... + 227429.

It is an arithmetic number, because the mean of its divisors is an integer number (4775169).

Almost surely, 2^18645857 is an apocalyptic number.

It is an amenable number.

18645857 is a deficient number, since it is larger than the sum of its proper divisors (454819).

18645857 is an equidigital number, since it uses as much as digits as its factorization.

18645857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454818.

The product of its digits is 268800, while the sum is 44.

The square root of 18645857 is about 4318.0848764238. The cubic root of 18645857 is about 265.1718690468.

The spelling of 18645857 in words is "eighteen million, six hundred forty-five thousand, eight hundred fifty-seven".