1278693651023 has 4 divisors (see below), whose sum is σ = 1278995020728. Its totient is φ = 1278392281320.

The previous prime is 1278693650999. The next prime is 1278693651029. The reversal of 1278693651023 is 3201563968721.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1278693651023 - 2³⁴ = 1261513781839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278693651029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150678488 + ... + 150686973.

It is an arithmetic number, because the mean of its divisors is an integer number (319748755182).

Almost surely, 2^{1278693651023} is an apocalyptic number.

1278693651023 is a deficient number, since it is larger than the sum of its proper divisors (301369705).

1278693651023 is an equidigital number, since it uses as much as digits as its factorization.

1278693651023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301369704.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 1278693651023 in words is "one trillion, two hundred seventy-eight billion, six hundred ninety-three million, six hundred fifty-one thousand, twenty-three".