20418397 has 4 divisors (see below), whose sum is σ = 20480416. Its totient is φ = 20356380.

The previous prime is 20418379. The next prime is 20418401. The reversal of 20418397 is 79381402.

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.

It is a cyclic number.

It is not a de Polignac number, because 20418397 - 2²³ = 12029789 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 (20418337) 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, 30513 + ... + 31174.

It is an arithmetic number, because the mean of its divisors is an integer number (5120104).

Almost surely, 2^20418397 is an apocalyptic number.

It is an amenable number.

20418397 is a deficient number, since it is larger than the sum of its proper divisors (62019).

20418397 is an equidigital number, since it uses as much as digits as its factorization.

20418397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62018.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20418397 is about 4518.6720394381. The cubic root of 20418397 is about 273.3215539573.

Adding to 20418397 its reverse (79381402), we get a palindrome (99799799).

The spelling of 20418397 in words is "twenty million, four hundred eighteen thousand, three hundred ninety-seven".