18620857 has 4 divisors (see below), whose sum is σ = 18754960. Its totient is φ = 18486756.

The previous prime is 18620843. The next prime is 18620873. The reversal of 18620857 is 75802681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75802681 = 47 ⋅1612823.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18620857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18620807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66843 + ... + 67120.

It is an arithmetic number, because the mean of its divisors is an integer number (4688740).

Almost surely, 2^18620857 is an apocalyptic number.

It is an amenable number.

18620857 is a deficient number, since it is larger than the sum of its proper divisors (134103).

18620857 is a wasteful number, since it uses less digits than its factorization.

18620857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134102.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 18620857 is about 4315.1891036199. The cubic root of 18620857 is about 265.0533036242.

The spelling of 18620857 in words is "eighteen million, six hundred twenty thousand, eight hundred fifty-seven".