1645742553979 has 2 divisors, whose sum is σ = 1645742553980. Its totient is φ = 1645742553978.

The previous prime is 1645742553977. The next prime is 1645742554007. The reversal of 1645742553979 is 9793552475461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1645742553979 - 2¹ = 1645742553977 is a prime.

It is a super-3 number, since 3×1645742553979³ (a number of 38 digits) contains 333 as substring.

Together with 1645742553977, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1645742553977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822871276989 + 822871276990.

It is an arithmetic number, because the mean of its divisors is an integer number (822871276990).

Almost surely, 2^{1645742553979} is an apocalyptic number.

1645742553979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645742553979 is an equidigital number, since it uses as much as digits as its factorization.

1645742553979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768000, while the sum is 67.

The spelling of 1645742553979 in words is "one trillion, six hundred forty-five billion, seven hundred forty-two million, five hundred fifty-three thousand, nine hundred seventy-nine".