646405455 has 32 divisors (see below), whose sum is σ = 1104339456. Its totient is φ = 322084224.

The previous prime is 646405453. The next prime is 646405457. The reversal of 646405455 is 554504646.

It is an interprime number because it is at equal distance from previous prime (646405453) and next prime (646405457).

It is not a de Polignac number, because 646405455 - 2¹ = 646405453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646405453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6952 + ... + 36621.

It is an arithmetic number, because the mean of its divisors is an integer number (34510608).

Almost surely, 2^646405455 is an apocalyptic number.

646405455 is a deficient number, since it is larger than the sum of its proper divisors (457934001).

646405455 is a wasteful number, since it uses less digits than its factorization.

646405455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43647.

The product of its (nonzero) digits is 288000, while the sum is 39.

The square root of 646405455 is about 25424.5050099309. The cubic root of 646405455 is about 864.6393654084.

The spelling of 646405455 in words is "six hundred forty-six million, four hundred five thousand, four hundred fifty-five".