21001000200073 has 2 divisors, whose sum is σ = 21001000200074. Its totient is φ = 21001000200072.

The previous prime is 21001000200053. The next prime is 21001000200091. The reversal of 21001000200073 is 37000200010012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18127609068409 + 2873391131664 = 4257653^2 + 1695108^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001000200073 - 2⁵ = 21001000200041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21001000200023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500500100036 + 10500500100037.

It is an arithmetic number, because the mean of its divisors is an integer number (10500500100037).

Almost surely, 2^{21001000200073} is an apocalyptic number.

It is an amenable number.

21001000200073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001000200073 is an equidigital number, since it uses as much as digits as its factorization.

21001000200073 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 16.

Adding to 21001000200073 its reverse (37000200010012), we get a palindrome (58001200210085).

The spelling of 21001000200073 in words is "twenty-one trillion, one billion, two hundred thousand, seventy-three".