20455191397 has 2 divisors, whose sum is σ = 20455191398. Its totient is φ = 20455191396.

The previous prime is 20455191389. The next prime is 20455191403. The reversal of 20455191397 is 79319155402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20241037441 + 214153956 = 142271^2 + 14634^2 .

It is a cyclic number.

It is not a de Polignac number, because 20455191397 - 2³ = 20455191389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20455197397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10227595698 + 10227595699.

It is an arithmetic number, because the mean of its divisors is an integer number (10227595699).

Almost surely, 2^20455191397 is an apocalyptic number.

It is an amenable number.

20455191397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20455191397 is an equidigital number, since it uses as much as digits as its factorization.

20455191397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 340200, while the sum is 46.

The spelling of 20455191397 in words is "twenty billion, four hundred fifty-five million, one hundred ninety-one thousand, three hundred ninety-seven".