665531745 has 32 divisors (see below), whose sum is σ = 1080566784. Its totient is φ = 349752000.

The previous prime is 665531731. The next prime is 665531807. The reversal of 665531745 is 547135566.

It is not a de Polignac number, because 665531745 - 2¹⁶ = 665466209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665531697 and 665531706.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 295594 + ... + 297836.

It is an arithmetic number, because the mean of its divisors is an integer number (33767712).

Almost surely, 2^665531745 is an apocalyptic number.

It is an amenable number.

665531745 is a deficient number, since it is larger than the sum of its proper divisors (415035039).

665531745 is a wasteful number, since it uses less digits than its factorization.

665531745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2533.

The product of its digits is 378000, while the sum is 42.

The square root of 665531745 is about 25797.9019495772. The cubic root of 665531745 is about 873.0844604682.

The spelling of 665531745 in words is "six hundred sixty-five million, five hundred thirty-one thousand, seven hundred forty-five".