1256651123 has 16 divisors (see below), whose sum is σ = 1596542976. Its totient is φ = 962197920.

The previous prime is 1256651117. The next prime is 1256651159. The reversal of 1256651123 is 3211566521.

It is a cyclic number.

It is not a de Polignac number, because 1256651123 - 2¹⁰ = 1256650099 is a prime.

It is a super-2 number, since 2×1256651123² = 3158344089874322258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1256651123.

It is not an unprimeable number, because it can be changed into a prime (1256657123) 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 15 ways as a sum of consecutive naturals, for example, 219911 + ... + 225552.

It is an arithmetic number, because the mean of its divisors is an integer number (99783936).

Almost surely, 2^1256651123 is an apocalyptic number.

1256651123 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1256651123 is a deficient number, since it is larger than the sum of its proper divisors (339891853).

1256651123 is a wasteful number, since it uses less digits than its factorization.

1256651123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445514.

The product of its digits is 10800, while the sum is 32.

The square root of 1256651123 is about 35449.2753522551. The cubic root of 1256651123 is about 1079.1245543320.

The spelling of 1256651123 in words is "one billion, two hundred fifty-six million, six hundred fifty-one thousand, one hundred twenty-three".