1398263557 has 4 divisors (see below), whose sum is σ = 1398699820. Its totient is φ = 1397827296.

The previous prime is 1398263539. The next prime is 1398263569. The reversal of 1398263557 is 7553628931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7553628931 = 59 ⋅128027609.

It can be written as a sum of positive squares in 2 ways, for example, as 163865601 + 1234397956 = 12801^2 + 35134^2 .

It is a cyclic number.

It is not a de Polignac number, because 1398263557 - 2⁷ = 1398263429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1398263557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398263527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213288 + ... + 219745.

It is an arithmetic number, because the mean of its divisors is an integer number (349674955).

Almost surely, 2^1398263557 is an apocalyptic number.

It is an amenable number.

1398263557 is a deficient number, since it is larger than the sum of its proper divisors (436263).

1398263557 is an equidigital number, since it uses as much as digits as its factorization.

1398263557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436262.

The product of its digits is 1360800, while the sum is 49.

The square root of 1398263557 is about 37393.3624725031. The cubic root of 1398263557 is about 1118.2262413057.

The spelling of 1398263557 in words is "one billion, three hundred ninety-eight million, two hundred sixty-three thousand, five hundred fifty-seven".