646402149 has 24 divisors (see below), whose sum is σ = 944917272. Its totient is φ = 425779200.

The previous prime is 646402103. The next prime is 646402157. The reversal of 646402149 is 941204646.

646402149 is a `hidden beast` number, since 6 + 4 + 640 + 2 + 1 + 4 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 160199649 + 486202500 = 12657^2 + 22050^2 .

It is not a de Polignac number, because 646402149 - 2⁸ = 646401893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646402349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 402949 + ... + 404549.

It is an arithmetic number, because the mean of its divisors is an integer number (39371553).

Almost surely, 2^646402149 is an apocalyptic number.

It is an amenable number.

646402149 is a deficient number, since it is larger than the sum of its proper divisors (298515123).

646402149 is a wasteful number, since it uses less digits than its factorization.

646402149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2117 (or 2114 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 646402149 is about 25424.4399938327. The cubic root of 646402149 is about 864.6378913581.

The spelling of 646402149 in words is "six hundred forty-six million, four hundred two thousand, one hundred forty-nine".