6405608016665 has 32 divisors (see below), whose sum is σ = 9505856304000. Its totient is φ = 4073938398720.

The previous prime is 6405608016649. The next prime is 6405608016697. The reversal of 6405608016665 is 5666108065046.

It is not a de Polignac number, because 6405608016665 - 2⁴ = 6405608016649 is a prime.

It is a Curzon number.

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, 235746740 + ... + 235773909.

It is an arithmetic number, because the mean of its divisors is an integer number (297058009500).

Almost surely, 2^{6405608016665} is an apocalyptic number.

6405608016665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6405608016665 is a deficient number, since it is larger than the sum of its proper divisors (3100248287335).

6405608016665 is a wasteful number, since it uses less digits than its factorization.

6405608016665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471520697.

The product of its (nonzero) digits is 6220800, while the sum is 53.

The spelling of 6405608016665 in words is "six trillion, four hundred five billion, six hundred eight million, sixteen thousand, six hundred sixty-five".