20418371 has 4 divisors (see below), whose sum is σ = 20553744. Its totient is φ = 20283000.

The previous prime is 20418361. The next prime is 20418373. The reversal of 20418371 is 17381402.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20418371 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20418371.

It is not an unprimeable number, because it can be changed into a prime (20418373) 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, 67460 + ... + 67761.

It is an arithmetic number, because the mean of its divisors is an integer number (5138436).

Almost surely, 2^20418371 is an apocalyptic number.

20418371 is a deficient number, since it is larger than the sum of its proper divisors (135373).

20418371 is a wasteful number, since it uses less digits than its factorization.

20418371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135372.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20418371 is about 4518.6691624858. The cubic root of 20418371 is about 273.3214379449.

Adding to 20418371 its reverse (17381402), we get a palindrome (37799773).

The spelling of 20418371 in words is "twenty million, four hundred eighteen thousand, three hundred seventy-one".