645555487 has 4 divisors (see below), whose sum is σ = 651823120. Its totient is φ = 639287856.

The previous prime is 645555479. The next prime is 645555541. The reversal of 645555487 is 784555546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645555487 - 2³ = 645555479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645555487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645555437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3133662 + ... + 3133867.

It is an arithmetic number, because the mean of its divisors is an integer number (162955780).

Almost surely, 2^645555487 is an apocalyptic number.

645555487 is a deficient number, since it is larger than the sum of its proper divisors (6267633).

645555487 is a wasteful number, since it uses less digits than its factorization.

645555487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6267632.

The product of its digits is 3360000, while the sum is 49.

The square root of 645555487 is about 25407.7839844407. The cubic root of 645555487 is about 864.2602235251.

The spelling of 645555487 in words is "six hundred forty-five million, five hundred fifty-five thousand, four hundred eighty-seven".