6398688391 has 16 divisors (see below), whose sum is σ = 6564013408. Its totient is φ = 6235574400.

The previous prime is 6398688379. The next prime is 6398688397. The reversal of 6398688391 is 1938868936.

It is a cyclic number.

It is not a de Polignac number, because 6398688391 - 2⁹ = 6398687879 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6398688397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3946561 + ... + 3948181.

It is an arithmetic number, because the mean of its divisors is an integer number (410250838).

Almost surely, 2^6398688391 is an apocalyptic number.

6398688391 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

6398688391 is a deficient number, since it is larger than the sum of its proper divisors (165325017).

6398688391 is a wasteful number, since it uses less digits than its factorization.

6398688391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2242.

The product of its digits is 13436928, while the sum is 61.

The square root of 6398688391 is about 79991.8020237074. The cubic root of 6398688391 is about 1856.5086924947.

The spelling of 6398688391 in words is "six billion, three hundred ninety-eight million, six hundred eighty-eight thousand, three hundred ninety-one".