18020357 has 4 divisors (see below), whose sum is σ = 19080396. Its totient is φ = 16960320.

The previous prime is 18020351. The next prime is 18020381. The reversal of 18020357 is 75302081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6145441 + 11874916 = 2479^2 + 3446^2 .

It is a cyclic number.

It is not a de Polignac number, because 18020357 - 2²⁰ = 16971781 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 (18020351) 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, 529994 + ... + 530027.

It is an arithmetic number, because the mean of its divisors is an integer number (4770099).

Almost surely, 2^18020357 is an apocalyptic number.

18020357 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18020357 is a deficient number, since it is larger than the sum of its proper divisors (1060039).

18020357 is a wasteful number, since it uses less digits than its factorization.

18020357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060038.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 18020357 is about 4245.0391046491. The cubic root of 18020357 is about 262.1728992969.

The spelling of 18020357 in words is "eighteen million, twenty thousand, three hundred fifty-seven".