648735989 has 16 divisors (see below), whose sum is σ = 727695360. Its totient is φ = 573216000.

The previous prime is 648735979. The next prime is 648736001. The reversal of 648735989 is 989537846.

It is a cyclic number.

It is not a de Polignac number, because 648735989 - 2¹² = 648731893 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648735959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124172 + ... + 129290.

It is an arithmetic number, because the mean of its divisors is an integer number (45480960).

Almost surely, 2^648735989 is an apocalyptic number.

It is an amenable number.

648735989 is a deficient number, since it is larger than the sum of its proper divisors (78959371).

648735989 is a wasteful number, since it uses less digits than its factorization.

648735989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5452.

The product of its digits is 13063680, while the sum is 59.

The square root of 648735989 is about 25470.2962095065. The cubic root of 648735989 is about 865.6772354564.

It can be divided in two parts, 648 and 735989, that added together give a palindrome (736637).

The spelling of 648735989 in words is "six hundred forty-eight million, seven hundred thirty-five thousand, nine hundred eighty-nine".