19870118 has 4 divisors (see below), whose sum is σ = 29805180. Its totient is φ = 9935058.

The previous prime is 19870111. The next prime is 19870129. The reversal of 19870118 is 81107891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81107891 = 73 ⋅1111067.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19870111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4967528 + ... + 4967531.

It is an arithmetic number, because the mean of its divisors is an integer number (7451295).

Almost surely, 2^19870118 is an apocalyptic number.

19870118 is a deficient number, since it is larger than the sum of its proper divisors (9935062).

19870118 is an equidigital number, since it uses as much as digits as its factorization.

19870118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9935061.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 19870118 is about 4457.5910534727. The cubic root of 19870118 is about 270.8528951130.

The spelling of 19870118 in words is "nineteen million, eight hundred seventy thousand, one hundred eighteen".