1211623727465 has 4 divisors (see below), whose sum is σ = 1453948472964. Its totient is φ = 969298981968.

The previous prime is 1211623727459. The next prime is 1211623727513. The reversal of 1211623727465 is 5647273261121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 427642755136 + 783980972329 = 653944^2 + 885427^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211623727465 - 2⁴ = 1211623727449 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 121162372742 + ... + 121162372751.

It is an arithmetic number, because the mean of its divisors is an integer number (363487118241).

Almost surely, 2^{1211623727465} is an apocalyptic number.

It is an amenable number.

1211623727465 is a deficient number, since it is larger than the sum of its proper divisors (242324745499).

1211623727465 is an equidigital number, since it uses as much as digits as its factorization.

1211623727465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242324745498.

The product of its digits is 846720, while the sum is 47.

Adding to 1211623727465 its reverse (5647273261121), we get a palindrome (6858896988586).

The spelling of 1211623727465 in words is "one trillion, two hundred eleven billion, six hundred twenty-three million, seven hundred twenty-seven thousand, four hundred sixty-five".