647958981 has 8 divisors (see below), whose sum is σ = 864838944. Its totient is φ = 431525840.

The previous prime is 647958979. The next prime is 647958989. The reversal of 647958981 is 189859746.

647958981 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 647958981 - 2¹ = 647958979 is a prime.

It is a super-2 number, since 2×647958981² = 839701682117116722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647958989) 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, 108306 + ... + 114131.

It is an arithmetic number, because the mean of its divisors is an integer number (108104868).

Almost surely, 2^647958981 is an apocalyptic number.

It is an amenable number.

647958981 is a deficient number, since it is larger than the sum of its proper divisors (216879963).

647958981 is a wasteful number, since it uses less digits than its factorization.

647958981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223411.

The product of its digits is 4354560, while the sum is 57.

The square root of 647958981 is about 25455.0384207135. The cubic root of 647958981 is about 865.3314826525.

The spelling of 647958981 in words is "six hundred forty-seven million, nine hundred fifty-eight thousand, nine hundred eighty-one".