645471 has 6 divisors (see below), whose sum is σ = 932360. Its totient is φ = 430308.

The previous prime is 645467. The next prime is 645481. The reversal of 645471 is 174546.

It is not a de Polignac number, because 645471 - 2² = 645467 is a prime.

It is a super-3 number, since 3×645471³ = 806773193075466333, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645431) 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 5 ways as a sum of consecutive naturals, for example, 35851 + ... + 35868.

2⁶⁴⁵⁴⁷¹ is an apocalyptic number.

645471 is a deficient number, since it is larger than the sum of its proper divisors (286889).

645471 is a wasteful number, since it uses less digits than its factorization.

645471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71725 (or 71722 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 645471 is about 803.4120984899. The cubic root of 645471 is about 86.4222518561.

The spelling of 645471 in words is "six hundred forty-five thousand, four hundred seventy-one".