21143240297 has 2 divisors, whose sum is σ = 21143240298. Its totient is φ = 21143240296.

The previous prime is 21143240281. The next prime is 21143240347. The reversal of 21143240297 is 79204234112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19348531801 + 1794708496 = 139099^2 + 42364^2 .

It is a cyclic number.

It is not a de Polignac number, because 21143240297 - 2⁴ = 21143240281 is a prime.

It is a super-2 number, since 2×21143240297² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21143240207) 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, 10571620148 + 10571620149.

It is an arithmetic number, because the mean of its divisors is an integer number (10571620149).

Almost surely, 2^21143240297 is an apocalyptic number.

It is an amenable number.

21143240297 is a deficient number, since it is larger than the sum of its proper divisors (1).

21143240297 is an equidigital number, since it uses as much as digits as its factorization.

21143240297 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 35.

The spelling of 21143240297 in words is "twenty-one billion, one hundred forty-three million, two hundred forty thousand, two hundred ninety-seven".