1216264540691 has 2 divisors, whose sum is σ = 1216264540692. Its totient is φ = 1216264540690.

The previous prime is 1216264540679. The next prime is 1216264540693. The reversal of 1216264540691 is 1960454626121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1216264540691 - 2²² = 1216260346387 is a prime.

Together with 1216264540693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1216264540693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608132270345 + 608132270346.

It is an arithmetic number, because the mean of its divisors is an integer number (608132270346).

Almost surely, 2^{1216264540691} is an apocalyptic number.

1216264540691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216264540691 is an equidigital number, since it uses as much as digits as its factorization.

1216264540691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 1216264540691 in words is "one trillion, two hundred sixteen billion, two hundred sixty-four million, five hundred forty thousand, six hundred ninety-one".