405666671 has 4 divisors (see below), whose sum is σ = 405757632. Its totient is φ = 405575712.

The previous prime is 405666661. The next prime is 405666673. The reversal of 405666671 is 176666504.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405666671 is a prime.

It is a super-4 number, since 4×405666671⁴ (a number of 36 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405666673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38426 + ... + 47831.

It is an arithmetic number, because the mean of its divisors is an integer number (101439408).

Almost surely, 2^405666671 is an apocalyptic number.

405666671 is a deficient number, since it is larger than the sum of its proper divisors (90961).

405666671 is an equidigital number, since it uses as much as digits as its factorization.

405666671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90960.

The product of its (nonzero) digits is 181440, while the sum is 41.

The square root of 405666671 is about 20141.1685609351. The cubic root of 405666671 is about 740.2693632243.

The spelling of 405666671 in words is "four hundred five million, six hundred sixty-six thousand, six hundred seventy-one".