18997605 has 48 divisors (see below), whose sum is σ = 37154880. Its totient is φ = 9203040.

The previous prime is 18997603. The next prime is 18997607. The reversal of 18997605 is 50679981.

It is an interprime number because it is at equal distance from previous prime (18997603) and next prime (18997607).

It is not a de Polignac number, because 18997605 - 2¹ = 18997603 is a prime.

It is a super-4 number, since 4×18997605⁴ (a number of 30 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18997603) 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 47 ways as a sum of consecutive naturals, for example, 15754 + ... + 16916.

It is an arithmetic number, because the mean of its divisors is an integer number (774060).

Almost surely, 2^18997605 is an apocalyptic number.

18997605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18997605 is a deficient number, since it is larger than the sum of its proper divisors (18157275).

18997605 is a wasteful number, since it uses less digits than its factorization.

18997605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1199 (or 1182 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 18997605 is about 4358.6242095414. The cubic root of 18997605 is about 266.8289524327.

The spelling of 18997605 in words is "eighteen million, nine hundred ninety-seven thousand, six hundred five".