571640981 has 2 divisors, whose sum is σ = 571640982. Its totient is φ = 571640980.

The previous prime is 571640947. The next prime is 571640999. The reversal of 571640981 is 189046175.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 464187025 + 107453956 = 21545^2 + 10366^2 .

It is a cyclic number.

It is not a de Polignac number, because 571640981 - 2¹⁸ = 571378837 is a prime.

It is a super-2 number, since 2×571640981² = 653546822317284722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (571640921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 285820490 + 285820491.

It is an arithmetic number, because the mean of its divisors is an integer number (285820491).

Almost surely, 2^571640981 is an apocalyptic number.

It is an amenable number.

571640981 is a deficient number, since it is larger than the sum of its proper divisors (1).

571640981 is an equidigital number, since it uses as much as digits as its factorization.

571640981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 571640981 is about 23909.0146388344. The cubic root of 571640981 is about 829.9293407696.

The spelling of 571640981 in words is "five hundred seventy-one million, six hundred forty thousand, nine hundred eighty-one".