1028196391 has 4 divisors (see below), whose sum is σ = 1028433384. Its totient is φ = 1027959400.

The previous prime is 1028196373. The next prime is 1028196409. The reversal of 1028196391 is 1936918201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1936918201 = 449 ⋅4313849.

It is an interprime number because it is at equal distance from previous prime (1028196373) and next prime (1028196409).

It is a cyclic number.

It is not a de Polignac number, because 1028196391 - 2⁵ = 1028196359 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 (1028196331) 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, 111865 + ... + 120706.

It is an arithmetic number, because the mean of its divisors is an integer number (257108346).

Almost surely, 2^1028196391 is an apocalyptic number.

1028196391 is a deficient number, since it is larger than the sum of its proper divisors (236993).

1028196391 is an equidigital number, since it uses as much as digits as its factorization.

1028196391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236992.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1028196391 is about 32065.5015710031. The cubic root of 1028196391 is about 1009.3118179049.

The spelling of 1028196391 in words is "one billion, twenty-eight million, one hundred ninety-six thousand, three hundred ninety-one".