21146543456369 has 2 divisors, whose sum is σ = 21146543456370. Its totient is φ = 21146543456368.

The previous prime is 21146543456287. The next prime is 21146543456443. The reversal of 21146543456369 is 96365434564112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20850730387600 + 295813068769 = 4566260^2 + 543887^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21146543456369 is a prime.

It is a super-2 number, since 2×21146543456369² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21146543476369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10573271728184 + 10573271728185.

It is an arithmetic number, because the mean of its divisors is an integer number (10573271728185).

Almost surely, 2^{21146543456369} is an apocalyptic number.

It is an amenable number.

21146543456369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146543456369 is an equidigital number, since it uses as much as digits as its factorization.

21146543456369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 55987200, while the sum is 59.

The spelling of 21146543456369 in words is "twenty-one trillion, one hundred forty-six billion, five hundred forty-three million, four hundred fifty-six thousand, three hundred sixty-nine".