21146004493 has 2 divisors, whose sum is σ = 21146004494. Its totient is φ = 21146004492.

The previous prime is 21146004491. The next prime is 21146004553. The reversal of 21146004493 is 39440064112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20574459844 + 571544649 = 143438^2 + 23907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21146004493 - 2¹ = 21146004491 is a prime.

Together with 21146004491, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21146004491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10573002246 + 10573002247.

It is an arithmetic number, because the mean of its divisors is an integer number (10573002247).

Almost surely, 2^21146004493 is an apocalyptic number.

It is an amenable number.

21146004493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146004493 is an equidigital number, since it uses as much as digits as its factorization.

21146004493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 34.

The spelling of 21146004493 in words is "twenty-one billion, one hundred forty-six million, four thousand, four hundred ninety-three".