20398579 has 2 divisors, whose sum is σ = 20398580. Its totient is φ = 20398578.

The previous prime is 20398577. The next prime is 20398627. The reversal of 20398579 is 97589302.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20398579 - 2¹ = 20398577 is a prime.

It is a super-2 number, since 2×20398579² = 832204050438482, which contains 22 as substring.

Together with 20398577, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20398577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10199289 + 10199290.

It is an arithmetic number, because the mean of its divisors is an integer number (10199290).

Almost surely, 2^20398579 is an apocalyptic number.

20398579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20398579 is an equidigital number, since it uses as much as digits as its factorization.

20398579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 20398579 is about 4516.4786061710. The cubic root of 20398579 is about 273.2330971280.

The spelling of 20398579 in words is "twenty million, three hundred ninety-eight thousand, five hundred seventy-nine".