1256997438975 has 24 divisors (see below), whose sum is σ = 2149899071760. Its totient is φ = 647281438720.

The previous prime is 1256997438959. The next prime is 1256997438979. The reversal of 1256997438975 is 5798347996521.

It is not a de Polignac number, because 1256997438975 - 2⁴ = 1256997438959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (75).

It is a junction number, because it is equal to n+sod(n) for n = 1256997438897 and 1256997438906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256997438979) 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 in 23 ways as a sum of consecutive naturals, for example, 288962754 + ... + 288967103.

It is an arithmetic number, because the mean of its divisors is an integer number (89579127990).

Almost surely, 2^{1256997438975} is an apocalyptic number.

1256997438975 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1256997438975 is a deficient number, since it is larger than the sum of its proper divisors (892901632785).

1256997438975 is a wasteful number, since it uses less digits than its factorization.

1256997438975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577929899 (or 577929894 counting only the distinct ones).

The product of its digits is 1028764800, while the sum is 75.

The spelling of 1256997438975 in words is "one trillion, two hundred fifty-six billion, nine hundred ninety-seven million, four hundred thirty-eight thousand, nine hundred seventy-five".