21304054397 has 2 divisors, whose sum is σ = 21304054398. Its totient is φ = 21304054396.

The previous prime is 21304054393. The next prime is 21304054427. The reversal of 21304054397 is 79345040312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10789807876 + 10514246521 = 103874^2 + 102539^2 .

It is a cyclic number.

It is not a de Polignac number, because 21304054397 - 2² = 21304054393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21304054397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21304054393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652027198 + 10652027199.

It is an arithmetic number, because the mean of its divisors is an integer number (10652027199).

Almost surely, 2^21304054397 is an apocalyptic number.

It is an amenable number.

21304054397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21304054397 is an equidigital number, since it uses as much as digits as its factorization.

21304054397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 38.

The spelling of 21304054397 in words is "twenty-one billion, three hundred four million, fifty-four thousand, three hundred ninety-seven".