1284457857 has 4 divisors (see below), whose sum is σ = 1712610480. Its totient is φ = 856305236.

The previous prime is 1284457847. The next prime is 1284457897. The reversal of 1284457857 is 7587544821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7587544821 = 3 ⋅2529181607.

It is a cyclic number.

It is not a de Polignac number, because 1284457857 - 2¹⁶ = 1284392321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1284457847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 214076307 + ... + 214076312.

It is an arithmetic number, because the mean of its divisors is an integer number (428152620).

Almost surely, 2^1284457857 is an apocalyptic number.

It is an amenable number.

1284457857 is a deficient number, since it is larger than the sum of its proper divisors (428152623).

1284457857 is an equidigital number, since it uses as much as digits as its factorization.

1284457857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428152622.

The product of its digits is 2508800, while the sum is 51.

The square root of 1284457857 is about 35839.3339363331. Note that the first 3 decimals coincide. The cubic root of 1284457857 is about 1087.0260534330.

The spelling of 1284457857 in words is "one billion, two hundred eighty-four million, four hundred fifty-seven thousand, eight hundred fifty-seven".