645416 has 8 divisors (see below), whose sum is σ = 1210170. Its totient is φ = 322704.

The previous prime is 645409. The next prime is 645419. The reversal of 645416 is 614546.

645416 = T₂₇₆ + T₂₇₇ + ... + T₂₉₁.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 624100 + 21316 = 790^2 + 146^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (645419) by changing a digit.

645416 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40331 + ... + 40346.

2⁶⁴⁵⁴¹⁶ is an apocalyptic number.

It is an amenable number.

645416 is a deficient number, since it is larger than the sum of its proper divisors (564754).

645416 is a wasteful number, since it uses less digits than its factorization.

645416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80683 (or 80679 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

The square root of 645416 is about 803.3778687517. The cubic root of 645416 is about 86.4197971324.

The spelling of 645416 in words is "six hundred forty-five thousand, four hundred sixteen".