646981543 has 8 divisors (see below), whose sum is σ = 698695200. Its totient is φ = 595545888.

The previous prime is 646981507. The next prime is 646981549. The reversal of 646981543 is 345189646.

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 646981543 - 2⁹ = 646981031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646981493 and 646981502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646981549) 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, 64648 + ... + 73981.

It is an arithmetic number, because the mean of its divisors is an integer number (87336900).

Almost surely, 2^646981543 is an apocalyptic number.

646981543 is a deficient number, since it is larger than the sum of its proper divisors (51713657).

646981543 is a wasteful number, since it uses less digits than its factorization.

646981543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139001.

The product of its digits is 622080, while the sum is 46.

The square root of 646981543 is about 25435.8318715941. The cubic root of 646981543 is about 864.8961497831.

The spelling of 646981543 in words is "six hundred forty-six million, nine hundred eighty-one thousand, five hundred forty-three".