1678620791997 has 12 divisors (see below), whose sum is σ = 2426573221020. Its totient is φ = 1118204184768.

The previous prime is 1678620791987. The next prime is 1678620792049. The reversal of 1678620791997 is 7991970268761.

It can be written as a sum of positive squares in 2 ways, for example, as 1283827229721 + 394793562276 = 1133061^2 + 628326^2 .

It is not a de Polignac number, because 1678620791997 - 2¹⁵ = 1678620759229 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1678620791987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73016472 + ... + 73039457.

It is an arithmetic number, because the mean of its divisors is an integer number (202214435085).

Almost surely, 2^{1678620791997} is an apocalyptic number.

It is an amenable number.

1678620791997 is a deficient number, since it is larger than the sum of its proper divisors (747952429023).

1678620791997 is a wasteful number, since it uses less digits than its factorization.

1678620791997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146057212 (or 146057209 counting only the distinct ones).

The product of its (nonzero) digits is 144027072, while the sum is 72.

The spelling of 1678620791997 in words is "one trillion, six hundred seventy-eight billion, six hundred twenty million, seven hundred ninety-one thousand, nine hundred ninety-seven".