1248555817 has 4 divisors (see below), whose sum is σ = 1269717840. Its totient is φ = 1227393796.

The previous prime is 1248555811. The next prime is 1248555863. The reversal of 1248555817 is 7185558421.

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: 7185558421 = 131 ⋅54851591.

It is a cyclic number.

It is not a de Polignac number, because 1248555817 - 2³ = 1248555809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1248555811) 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, 10580923 + ... + 10581040.

It is an arithmetic number, because the mean of its divisors is an integer number (317429460).

Almost surely, 2^1248555817 is an apocalyptic number.

It is an amenable number.

1248555817 is a deficient number, since it is larger than the sum of its proper divisors (21162023).

1248555817 is an equidigital number, since it uses as much as digits as its factorization.

1248555817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21162022.

The product of its digits is 448000, while the sum is 46.

The square root of 1248555817 is about 35334.9093249155. The cubic root of 1248555817 is about 1076.8023320865.

The spelling of 1248555817 in words is "one billion, two hundred forty-eight million, five hundred fifty-five thousand, eight hundred seventeen".