21000011011237 has 2 divisors, whose sum is σ = 21000011011238. Its totient is φ = 21000011011236.

The previous prime is 21000011011163. The next prime is 21000011011249. The reversal of 21000011011237 is 73211011000012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15807669484996 + 5192341526241 = 3975886^2 + 2278671^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000011011237 - 2²³ = 21000002622629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000011011937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500005505618 + 10500005505619.

It is an arithmetic number, because the mean of its divisors is an integer number (10500005505619).

Almost surely, 2^{21000011011237} is an apocalyptic number.

It is an amenable number.

21000011011237 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000011011237 is an equidigital number, since it uses as much as digits as its factorization.

21000011011237 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 19.

Adding to 21000011011237 its reverse (73211011000012), we get a palindrome (94211022011249).

The spelling of 21000011011237 in words is "twenty-one trillion, eleven million, eleven thousand, two hundred thirty-seven".