1256512401 has 12 divisors (see below), whose sum is σ = 1819633140. Its totient is φ = 835519200.

The previous prime is 1256512399. The next prime is 1256512403. The reversal of 1256512401 is 1042156521.

1256512401 is a `hidden beast` number, since 1 + 2 + 5 + 651 + 2 + 4 + 0 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1256512399) and next prime (1256512403).

It can be written as a sum of positive squares in 2 ways, for example, as 915002001 + 341510400 = 30249^2 + 18480^2 .

It is not a de Polignac number, because 1256512401 - 2¹ = 1256512399 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1256512403) 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, 175950 + ... + 182951.

It is an arithmetic number, because the mean of its divisors is an integer number (151636095).

Almost surely, 2^1256512401 is an apocalyptic number.

It is an amenable number.

1256512401 is a deficient number, since it is larger than the sum of its proper divisors (563120739).

1256512401 is a wasteful number, since it uses less digits than its factorization.

1256512401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359296 (or 359293 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 1256512401 is about 35447.3186715159. The cubic root of 1256512401 is about 1079.0848446033.

Adding to 1256512401 its reverse (1042156521), we get a palindrome (2298668922).

The spelling of 1256512401 in words is "one billion, two hundred fifty-six million, five hundred twelve thousand, four hundred one".