571231661 has 36 divisors (see below), whose sum is σ = 785078784. Its totient is φ = 410810400.

The previous prime is 571231627. The next prime is 571231673. The reversal of 571231661 is 166132175.

It is not a de Polignac number, because 571231661 - 2⁶ = 571231597 is a prime.

It is a super-2 number, since 2×571231661² = 652611221057637842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (571231691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 87956 + ... + 94226.

It is an arithmetic number, because the mean of its divisors is an integer number (21807744).

Almost surely, 2^571231661 is an apocalyptic number.

It is an amenable number.

571231661 is a deficient number, since it is larger than the sum of its proper divisors (213847123).

571231661 is a wasteful number, since it uses less digits than its factorization.

571231661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6322 (or 6302 counting only the distinct ones).

The product of its digits is 7560, while the sum is 32.

The square root of 571231661 is about 23900.4531546998. The cubic root of 571231661 is about 829.7312048749.

It can be divided in two parts, 5712 and 31661, that added together give a palindrome (37373).

The spelling of 571231661 in words is "five hundred seventy-one million, two hundred thirty-one thousand, six hundred sixty-one".