20455397 has 2 divisors, whose sum is σ = 20455398. Its totient is φ = 20455396.

The previous prime is 20455363. The next prime is 20455417. The reversal of 20455397 is 79355402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20349121 + 106276 = 4511^2 + 326^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20455397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20455307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10227698 + 10227699.

It is an arithmetic number, because the mean of its divisors is an integer number (10227699).

Almost surely, 2^20455397 is an apocalyptic number.

It is an amenable number.

20455397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20455397 is an equidigital number, since it uses as much as digits as its factorization.

20455397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37800, while the sum is 35.

The square root of 20455397 is about 4522.7643095788. The cubic root of 20455397 is about 273.4865488741.

The spelling of 20455397 in words is "twenty million, four hundred fifty-five thousand, three hundred ninety-seven".