21121300073 has 2 divisors, whose sum is σ = 21121300074. Its totient is φ = 21121300072.

The previous prime is 21121300051. The next prime is 21121300103. The reversal of 21121300073 is 37000312112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14728977769 + 6392322304 = 121363^2 + 79952^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121300073 - 2²⁰ = 21120251497 is a prime.

It is a super-2 number, since 2×21121300073² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121300003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560650036 + 10560650037.

It is an arithmetic number, because the mean of its divisors is an integer number (10560650037).

Almost surely, 2^21121300073 is an apocalyptic number.

It is an amenable number.

21121300073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121300073 is an equidigital number, since it uses as much as digits as its factorization.

21121300073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 20.

Adding to 21121300073 its reverse (37000312112), we get a palindrome (58121612185).

The spelling of 21121300073 in words is "twenty-one billion, one hundred twenty-one million, three hundred thousand, seventy-three".