646689481 has 8 divisors (see below), whose sum is σ = 668438784. Its totient is φ = 624995760.

The previous prime is 646689467. The next prime is 646689493. The reversal of 646689481 is 184986646.

646689481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 646689481 - 2¹³ = 646681289 is a prime.

It is a super-2 number, since 2×646689481² = 836414569672098722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646689431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10470 + ... + 37456.

It is an arithmetic number, because the mean of its divisors is an integer number (83554848).

Almost surely, 2^646689481 is an apocalyptic number.

It is an amenable number.

646689481 is a deficient number, since it is larger than the sum of its proper divisors (21749303).

646689481 is a wasteful number, since it uses less digits than its factorization.

646689481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27791.

The product of its digits is 1990656, while the sum is 52.

The square root of 646689481 is about 25430.0900706230. The cubic root of 646689481 is about 864.7659856788.

The spelling of 646689481 in words is "six hundred forty-six million, six hundred eighty-nine thousand, four hundred eighty-one".