21000134893237 has 2 divisors, whose sum is σ = 21000134893238. Its totient is φ = 21000134893236.

The previous prime is 21000134893057. The next prime is 21000134893277. The reversal of 21000134893237 is 73239843100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16716927985956 + 4283206907281 = 4088634^2 + 2069591^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000134893237 - 2¹⁵ = 21000134860469 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000134893193 and 21000134893202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000134893277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500067446618 + 10500067446619.

It is an arithmetic number, because the mean of its divisors is an integer number (10500067446619).

Almost surely, 2^{21000134893237} is an apocalyptic number.

It is an amenable number.

21000134893237 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000134893237 is an equidigital number, since it uses as much as digits as its factorization.

21000134893237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 43.

Adding to 21000134893237 its reverse (73239843100012), we get a palindrome (94239977993249).

The spelling of 21000134893237 in words is "twenty-one trillion, one hundred thirty-four million, eight hundred ninety-three thousand, two hundred thirty-seven".