646121105 has 40 divisors (see below), whose sum is σ = 914784192. Its totient is φ = 438041184.

The previous prime is 646121101. The next prime is 646121107. The reversal of 646121105 is 501121646.

It is not a de Polignac number, because 646121105 - 2² = 646121101 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646121101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1284284 + ... + 1284786.

Almost surely, 2^646121105 is an apocalyptic number.

It is an amenable number.

646121105 is a deficient number, since it is larger than the sum of its proper divisors (268663087).

646121105 is an equidigital number, since it uses as much as digits as its factorization.

646121105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 622 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 646121105 is about 25418.9123488791. The cubic root of 646121105 is about 864.5125635375.

The spelling of 646121105 in words is "six hundred forty-six million, one hundred twenty-one thousand, one hundred five".