1211421657599 has 2 divisors, whose sum is σ = 1211421657600. Its totient is φ = 1211421657598.

The previous prime is 1211421657569. The next prime is 1211421657601. The reversal of 1211421657599 is 9957561241121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211421657599 - 2¹² = 1211421653503 is a prime.

It is a super-3 number, since 3×1211421657599³ (a number of 37 digits) contains 333 as substring.

Together with 1211421657601, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211421657599.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211421657559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605710828799 + 605710828800.

It is an arithmetic number, because the mean of its divisors is an integer number (605710828800).

Almost surely, 2^{1211421657599} is an apocalyptic number.

1211421657599 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211421657599 is an equidigital number, since it uses as much as digits as its factorization.

1211421657599 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1360800, while the sum is 53.

The spelling of 1211421657599 in words is "one trillion, two hundred eleven billion, four hundred twenty-one million, six hundred fifty-seven thousand, five hundred ninety-nine".