645489441 has 24 divisors (see below), whose sum is σ = 951912000. Its totient is φ = 421366752.

The previous prime is 645489437. The next prime is 645489443. The reversal of 645489441 is 144984546.

645489441 is a `hidden beast` number, since 64 + 548 + 9 + 4 + 41 = 666.

It is not a de Polignac number, because 645489441 - 2² = 645489437 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645489443) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140580 + ... + 145098.

It is an arithmetic number, because the mean of its divisors is an integer number (39663000).

Almost surely, 2^645489441 is an apocalyptic number.

It is an amenable number.

645489441 is a deficient number, since it is larger than the sum of its proper divisors (306422559).

645489441 is a wasteful number, since it uses less digits than its factorization.

645489441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4853 (or 4850 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The square root of 645489441 is about 25406.4842313926. The cubic root of 645489441 is about 864.2307487143.

The spelling of 645489441 in words is "six hundred forty-five million, four hundred eighty-nine thousand, four hundred forty-one".