1661392346879 has 2 divisors, whose sum is σ = 1661392346880. Its totient is φ = 1661392346878.

The previous prime is 1661392346827. The next prime is 1661392346897. The reversal of 1661392346879 is 9786432931661.

Together with next prime (1661392346897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661392346879 - 2⁸ = 1661392346623 is a prime.

It is a super-2 number, since 2×1661392346879² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661392346819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830696173439 + 830696173440.

It is an arithmetic number, because the mean of its divisors is an integer number (830696173440).

Almost surely, 2^{1661392346879} is an apocalyptic number.

1661392346879 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661392346879 is an equidigital number, since it uses as much as digits as its factorization.

1661392346879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70543872, while the sum is 65.

The spelling of 1661392346879 in words is "one trillion, six hundred sixty-one billion, three hundred ninety-two million, three hundred forty-six thousand, eight hundred seventy-nine".