646989646 has 4 divisors (see below), whose sum is σ = 970484472. Its totient is φ = 323494822.

The previous prime is 646989641. The next prime is 646989647.

646989646 is nontrivially palindromic in base 10.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646989641) 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 as a sum of consecutive naturals, namely, 161747410 + ... + 161747413.

It is an arithmetic number, because the mean of its divisors is an integer number (242621118).

Almost surely, 2^646989646 is an apocalyptic number.

646989646 is a deficient number, since it is larger than the sum of its proper divisors (323494826).

646989646 is a wasteful number, since it uses less digits than its factorization.

646989646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323494825.

The product of its digits is 13436928, while the sum is 58.

The square root of 646989646 is about 25435.9911542680. The cubic root of 646989646 is about 864.8997605117.

The spelling of 646989646 in words is "six hundred forty-six million, nine hundred eighty-nine thousand, six hundred forty-six".