571981 has 4 divisors (see below), whose sum is σ = 590464. Its totient is φ = 553500.

The previous prime is 571973. The next prime is 572023. The reversal of 571981 is 189175.

571981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 571981 - 2³ = 571973 is a prime.

It is a super-2 number, since 2×571981² = 654324528722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 18451 = 571981 / (5 + 7 + 1 + 9 + 8 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (571381) 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, 9195 + ... + 9256.

It is an arithmetic number, because the mean of its divisors is an integer number (147616).

2⁵⁷¹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

571981 is a deficient number, since it is larger than the sum of its proper divisors (18483).

571981 is a wasteful number, since it uses less digits than its factorization.

571981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18482.

The product of its digits is 2520, while the sum is 31.

The square root of 571981 is about 756.2942549035. The cubic root of 571981 is about 83.0093858839.

The spelling of 571981 in words is "five hundred seventy-one thousand, nine hundred eighty-one".