6427991865 has 32 divisors (see below), whose sum is σ = 10386288000. Its totient is φ = 3394575360.

The previous prime is 6427991837. The next prime is 6427991891. The reversal of 6427991865 is 5681997246.

It is not a de Polignac number, because 6427991865 - 2¹¹ = 6427989817 is a prime.

It is a super-4 number, since 4×6427991865⁴ (a number of 40 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 735441 + ... + 744129.

It is an arithmetic number, because the mean of its divisors is an integer number (324571500).

Almost surely, 2^6427991865 is an apocalyptic number.

It is an amenable number.

6427991865 is a deficient number, since it is larger than the sum of its proper divisors (3958296135).

6427991865 is a wasteful number, since it uses less digits than its factorization.

6427991865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9177.

The product of its digits is 6531840, while the sum is 57.

The square root of 6427991865 is about 80174.7582784008. The cubic root of 6427991865 is about 1859.3384035600.

The spelling of 6427991865 in words is "six billion, four hundred twenty-seven million, nine hundred ninety-one thousand, eight hundred sixty-five".