564221981 has 4 divisors (see below), whose sum is σ = 576226752. Its totient is φ = 552217212.

The previous prime is 564221971. The next prime is 564222007. The reversal of 564221981 is 189122465.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 564221981 - 2¹⁰ = 564220957 is a prime.

It is a super-2 number, since 2×564221981² = 636692887687128722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (564221971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6002315 + ... + 6002408.

It is an arithmetic number, because the mean of its divisors is an integer number (144056688).

Almost surely, 2^564221981 is an apocalyptic number.

It is an amenable number.

564221981 is a deficient number, since it is larger than the sum of its proper divisors (12004771).

564221981 is a wasteful number, since it uses less digits than its factorization.

564221981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12004770.

The product of its digits is 34560, while the sum is 38.

The square root of 564221981 is about 23753.3572574489. The cubic root of 564221981 is about 826.3233031566.

The spelling of 564221981 in words is "five hundred sixty-four million, two hundred twenty-one thousand, nine hundred eighty-one".