665726545 has 16 divisors (see below), whose sum is σ = 922762368. Its totient is φ = 455683840.

The previous prime is 665726543. The next prime is 665726569. The reversal of 665726545 is 545627566.

It is not a de Polignac number, because 665726545 - 2¹ = 665726543 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 665726495 and 665726504.

It is not an unprimeable number, because it can be changed into a prime (665726543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 355069 + ... + 356938.

It is an arithmetic number, because the mean of its divisors is an integer number (57672648).

Almost surely, 2^665726545 is an apocalyptic number.

It is an amenable number.

665726545 is a deficient number, since it is larger than the sum of its proper divisors (257035823).

665726545 is a wasteful number, since it uses less digits than its factorization.

665726545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712040.

The product of its digits is 1512000, while the sum is 46.

The square root of 665726545 is about 25801.6771741683. The cubic root of 665726545 is about 873.1696355998.

The spelling of 665726545 in words is "six hundred sixty-five million, seven hundred twenty-six thousand, five hundred forty-five".