21211000073 has 2 divisors, whose sum is σ = 21211000074. Its totient is φ = 21211000072.

The previous prime is 21210999989. The next prime is 21211000087. The reversal of 21211000073 is 37000011212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21207514384 + 3485689 = 145628^2 + 1867^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211000073 - 2³⁰ = 20137258249 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211000973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605500036 + 10605500037.

It is an arithmetic number, because the mean of its divisors is an integer number (10605500037).

Almost surely, 2^21211000073 is an apocalyptic number.

It is an amenable number.

21211000073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211000073 is an equidigital number, since it uses as much as digits as its factorization.

21211000073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 17.

Adding to 21211000073 its reverse (37000011212), we get a palindrome (58211011285).

The spelling of 21211000073 in words is "twenty-one billion, two hundred eleven million, seventy-three", and thus it is an aban number.