40643566665405 has 32 divisors (see below), whose sum is σ = 70964113523328. Its totient is φ = 19699689676800.

The previous prime is 40643566665389. The next prime is 40643566665409. The reversal of 40643566665405 is 50456666534604.

It is not a de Polignac number, because 40643566665405 - 2⁴ = 40643566665389 is a prime.

It is a super-2 number, since 2×40643566665405² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40643566665409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38743576 + ... + 39778785.

It is an arithmetic number, because the mean of its divisors is an integer number (2217628547604).

Almost surely, 2^{40643566665405} is an apocalyptic number.

It is an amenable number.

40643566665405 is a deficient number, since it is larger than the sum of its proper divisors (30320546857923).

40643566665405 is a wasteful number, since it uses less digits than its factorization.

40643566665405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78525517.

The product of its (nonzero) digits is 186624000, while the sum is 60.

The spelling of 40643566665405 in words is "forty trillion, six hundred forty-three billion, five hundred sixty-six million, six hundred sixty-five thousand, four hundred five".