1321555646051 has 2 divisors, whose sum is σ = 1321555646052. Its totient is φ = 1321555646050.

The previous prime is 1321555646039. The next prime is 1321555646053. The reversal of 1321555646051 is 1506465551231.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321555646051 is a prime.

Together with 1321555646053, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321555645993 and 1321555646011.

It is not a weakly prime, because it can be changed into another prime (1321555646053) 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, 660777823025 + 660777823026.

It is an arithmetic number, because the mean of its divisors is an integer number (660777823026).

Almost surely, 2^{1321555646051} is an apocalyptic number.

1321555646051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321555646051 is an equidigital number, since it uses as much as digits as its factorization.

1321555646051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540000, while the sum is 44.

The spelling of 1321555646051 in words is "one trillion, three hundred twenty-one billion, five hundred fifty-five million, six hundred forty-six thousand, fifty-one".