1256172969 has 8 divisors (see below), whose sum is σ = 1676801952. Its totient is φ = 836496320.

The previous prime is 1256172947. The next prime is 1256172997. The reversal of 1256172969 is 9692716521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1256172969 - 2⁵ = 1256172937 is a prime.

It is a super-2 number, since 2×1256172969² = 3155941056092549922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1256172569) 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 7 ways as a sum of consecutive naturals, for example, 234999 + ... + 240284.

It is an arithmetic number, because the mean of its divisors is an integer number (209600244).

Almost surely, 2^1256172969 is an apocalyptic number.

It is an amenable number.

1256172969 is a deficient number, since it is larger than the sum of its proper divisors (420628983).

1256172969 is an equidigital number, since it uses as much as digits as its factorization.

1256172969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476167.

The product of its digits is 408240, while the sum is 48.

The square root of 1256172969 is about 35442.5305106732. The cubic root of 1256172969 is about 1078.9876685061.

The spelling of 1256172969 in words is "one billion, two hundred fifty-six million, one hundred seventy-two thousand, nine hundred sixty-nine".