1256261151 has 4 divisors (see below), whose sum is σ = 1675014872. Its totient is φ = 837507432.

The previous prime is 1256261131. The next prime is 1256261183. The reversal of 1256261151 is 1511626521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1511626521 = 3 ⋅503875507.

It is not a de Polignac number, because 1256261151 - 2¹⁹ = 1255736863 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 (1256261101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209376856 + ... + 209376861.

It is an arithmetic number, because the mean of its divisors is an integer number (418753718).

Almost surely, 2^1256261151 is an apocalyptic number.

1256261151 is a deficient number, since it is larger than the sum of its proper divisors (418753721).

1256261151 is an equidigital number, since it uses as much as digits as its factorization.

1256261151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418753720.

The product of its digits is 3600, while the sum is 30.

The square root of 1256261151 is about 35443.7745027247. The cubic root of 1256261151 is about 1079.0129158425.

Adding to 1256261151 its reverse (1511626521), we get a palindrome (2767887672).

The spelling of 1256261151 in words is "one billion, two hundred fifty-six million, two hundred sixty-one thousand, one hundred fifty-one".