531415665 has 72 divisors (see below), whose sum is σ = 1072215144. Its totient is φ = 242457600.

The previous prime is 531415649. The next prime is 531415681. The reversal of 531415665 is 566514135.

531415665 is a `hidden beast` number, since 53 + 1 + 41 + 566 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (531415649) and next prime (531415681).

It can be written as a sum of positive squares in 4 ways, for example, as 108743184 + 422672481 = 10428^2 + 20559^2 .

It is not a de Polignac number, because 531415665 - 2⁴ = 531415649 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 89695 + ... + 95435.

It is an arithmetic number, because the mean of its divisors is an integer number (14891877).

Almost surely, 2^531415665 is an apocalyptic number.

531415665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

531415665 is an abundant number, since it is smaller than the sum of its proper divisors (540799479).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

531415665 is a wasteful number, since it uses less digits than its factorization.

531415665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5791 (or 5777 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 531415665 is about 23052.4546415344. The cubic root of 531415665 is about 809.9871282820.

The spelling of 531415665 in words is "five hundred thirty-one million, four hundred fifteen thousand, six hundred sixty-five".