1291256417 has 32 divisors (see below), whose sum is σ = 1473500160. Its totient is φ = 1121400000.

The previous prime is 1291256347. The next prime is 1291256441. The reversal of 1291256417 is 7146521921.

It is a cyclic number.

It is not a de Polignac number, because 1291256417 - 2¹² = 1291252321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1291256467) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7213634 + ... + 7213812.

It is an arithmetic number, because the mean of its divisors is an integer number (46046880).

Almost surely, 2^1291256417 is an apocalyptic number.

It is an amenable number.

1291256417 is a deficient number, since it is larger than the sum of its proper divisors (182243743).

1291256417 is a wasteful number, since it uses less digits than its factorization.

1291256417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485.

The product of its digits is 30240, while the sum is 38.

The square root of 1291256417 is about 35934.0565063284. The cubic root of 1291256417 is about 1088.9405346696.

The spelling of 1291256417 in words is "one billion, two hundred ninety-one million, two hundred fifty-six thousand, four hundred seventeen".