646756749 has 12 divisors (see below), whose sum is σ = 934432512. Its totient is φ = 431065800.

The previous prime is 646756729. The next prime is 646756763. The reversal of 646756749 is 947657646.

646756749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 646756749 - 2⁵ = 646756717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 646756695 and 646756704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646756729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52884 + ... + 63954.

It is an arithmetic number, because the mean of its divisors is an integer number (77869376).

Almost surely, 2^646756749 is an apocalyptic number.

It is an amenable number.

646756749 is a deficient number, since it is larger than the sum of its proper divisors (287675763).

646756749 is a wasteful number, since it uses less digits than its factorization.

646756749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17568 (or 17565 counting only the distinct ones).

The product of its digits is 7620480, while the sum is 54.

The square root of 646756749 is about 25431.4126426355. The cubic root of 646756749 is about 864.7959686733.

The spelling of 646756749 in words is "six hundred forty-six million, seven hundred fifty-six thousand, seven hundred forty-nine".