564723981 has 24 divisors (see below), whose sum is σ = 847566720. Its totient is φ = 375751872.

The previous prime is 564723977. The next prime is 564724019. The reversal of 564723981 is 189327465.

564723981 is a `hidden beast` number, since 564 + 7 + 2 + 3 + 9 + 81 = 666.

It is not a de Polignac number, because 564723981 - 2² = 564723977 is a prime.

It is a super-2 number, since 2×564723981² = 637826349432976722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (564723911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 142140 + ... + 146058.

It is an arithmetic number, because the mean of its divisors is an integer number (35315280).

Almost surely, 2^564723981 is an apocalyptic number.

It is an amenable number.

564723981 is a deficient number, since it is larger than the sum of its proper divisors (282842739).

564723981 is an equidigital number, since it uses as much as digits as its factorization.

564723981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4527 (or 4515 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 564723981 is about 23763.9218354210. The cubic root of 564723981 is about 826.5682961735.

The spelling of 564723981 in words is "five hundred sixty-four million, seven hundred twenty-three thousand, nine hundred eighty-one".