20398501 has 2 divisors, whose sum is σ = 20398502. Its totient is φ = 20398500.

The previous prime is 20398489. The next prime is 20398529. The reversal of 20398501 is 10589302.

It is an a-pointer prime, because the next prime (20398529) can be obtained adding 20398501 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16402500 + 3996001 = 4050^2 + 1999^2 .

It is a cyclic number.

It is not a de Polignac number, because 20398501 - 2¹³ = 20390309 is a prime.

It is a Chen prime.

It is equal to p_1294273 and since 20398501 and 1294273 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20398501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20398531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10199250 + 10199251.

It is an arithmetic number, because the mean of its divisors is an integer number (10199251).

Almost surely, 2^20398501 is an apocalyptic number.

It is an amenable number.

20398501 is a deficient number, since it is larger than the sum of its proper divisors (1).

20398501 is an equidigital number, since it uses as much as digits as its factorization.

20398501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 20398501 is about 4516.4699711168. The cubic root of 20398501 is about 273.2327488651.

The spelling of 20398501 in words is "twenty million, three hundred ninety-eight thousand, five hundred one".