6428091391 has 4 divisors (see below), whose sum is σ = 6806214432. Its totient is φ = 6049968352.

The previous prime is 6428091337. The next prime is 6428091407. The reversal of 6428091391 is 1931908246.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6428091391 - 2²⁹ = 5891220479 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 (6428091311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189061495 + ... + 189061528.

It is an arithmetic number, because the mean of its divisors is an integer number (1701553608).

Almost surely, 2^6428091391 is an apocalyptic number.

6428091391 is a deficient number, since it is larger than the sum of its proper divisors (378123041).

6428091391 is a wasteful number, since it uses less digits than its factorization.

6428091391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378123040.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 6428091391 is about 80175.3789576326. The cubic root of 6428091391 is about 1859.3479996912.

The spelling of 6428091391 in words is "six billion, four hundred twenty-eight million, ninety-one thousand, three hundred ninety-one".