6397515391 has 4 divisors (see below), whose sum is σ = 6618119400. Its totient is φ = 6176911384.

The previous prime is 6397515373. The next prime is 6397515407. The reversal of 6397515391 is 1935157936.

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 6397515391 - 2¹⁹ = 6396991103 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6397515331) 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, 110301961 + ... + 110302018.

It is an arithmetic number, because the mean of its divisors is an integer number (1654529850).

Almost surely, 2^6397515391 is an apocalyptic number.

6397515391 is a deficient number, since it is larger than the sum of its proper divisors (220604009).

6397515391 is a wasteful number, since it uses less digits than its factorization.

6397515391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220604008.

The product of its digits is 765450, while the sum is 49.

The square root of 6397515391 is about 79984.4696863085. The cubic root of 6397515391 is about 1856.3952412347.

The spelling of 6397515391 in words is "six billion, three hundred ninety-seven million, five hundred fifteen thousand, three hundred ninety-one".