21730409201 has 2 divisors, whose sum is σ = 21730409202. Its totient is φ = 21730409200.

The previous prime is 21730409153. The next prime is 21730409243. The reversal of 21730409201 is 10290403712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15166168801 + 6564240400 = 123151^2 + 81020^2 .

It is a cyclic number.

It is not a de Polignac number, because 21730409201 - 2¹⁸ = 21730147057 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21730499201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10865204600 + 10865204601.

It is an arithmetic number, because the mean of its divisors is an integer number (10865204601).

Almost surely, 2^21730409201 is an apocalyptic number.

It is an amenable number.

21730409201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21730409201 is an equidigital number, since it uses as much as digits as its factorization.

21730409201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The spelling of 21730409201 in words is "twenty-one billion, seven hundred thirty million, four hundred nine thousand, two hundred one".