21800270197 has 2 divisors, whose sum is σ = 21800270198. Its totient is φ = 21800270196.

The previous prime is 21800270123. The next prime is 21800270221. The reversal of 21800270197 is 79107200812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13085300881 + 8714969316 = 114391^2 + 93354^2 .

It is a cyclic number.

It is not a de Polignac number, because 21800270197 - 2²³ = 21791881589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21800270117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10900135098 + 10900135099.

It is an arithmetic number, because the mean of its divisors is an integer number (10900135099).

Almost surely, 2^21800270197 is an apocalyptic number.

It is an amenable number.

21800270197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21800270197 is an equidigital number, since it uses as much as digits as its factorization.

21800270197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 37.

The spelling of 21800270197 in words is "twenty-one billion, eight hundred million, two hundred seventy thousand, one hundred ninety-seven".