665461131 has 4 divisors (see below), whose sum is σ = 887281512. Its totient is φ = 443640752.

The previous prime is 665461129. The next prime is 665461189. The reversal of 665461131 is 131164566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 665461131 - 2¹ = 665461129 is a prime.

It is a super-2 number, since 2×665461131² = 885677033743598322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 665461092 and 665461101.

It is not an unprimeable number, because it can be changed into a prime (665463131) 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, 110910186 + ... + 110910191.

It is an arithmetic number, because the mean of its divisors is an integer number (221820378).

Almost surely, 2^665461131 is an apocalyptic number.

665461131 is a deficient number, since it is larger than the sum of its proper divisors (221820381).

665461131 is a wasteful number, since it uses less digits than its factorization.

665461131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221820380.

The product of its digits is 12960, while the sum is 33.

The square root of 665461131 is about 25796.5333136063. The cubic root of 665461131 is about 873.0535808159.

The spelling of 665461131 in words is "six hundred sixty-five million, four hundred sixty-one thousand, one hundred thirty-one".