21234100897 has 2 divisors, whose sum is σ = 21234100898. Its totient is φ = 21234100896.

The previous prime is 21234100879. The next prime is 21234100931. The reversal of 21234100897 is 79800143212.

Together with previous prime (21234100879) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18887279761 + 2346821136 = 137431^2 + 48444^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234100897 - 2¹⁵ = 21234068129 is a prime.

It is not a weakly prime, because it can be changed into another prime (21234100837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617050448 + 10617050449.

It is an arithmetic number, because the mean of its divisors is an integer number (10617050449).

Almost surely, 2^21234100897 is an apocalyptic number.

It is an amenable number.

21234100897 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234100897 is an equidigital number, since it uses as much as digits as its factorization.

21234100897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 37.

The spelling of 21234100897 in words is "twenty-one billion, two hundred thirty-four million, one hundred thousand, eight hundred ninety-seven".