645648786 has 16 divisors (see below), whose sum is σ = 1434775200. Its totient is φ = 215216244.

The previous prime is 645648767. The next prime is 645648791. The reversal of 645648786 is 687846546.

645648786 is a `hidden beast` number, since 6 + 4 + 564 + 8 + 78 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 11956459 = 645648786 / (6 + 4 + 5 + 6 + 4 + 8 + 7 + 8 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5978176 + ... + 5978283.

It is an arithmetic number, because the mean of its divisors is an integer number (89673450).

Almost surely, 2^645648786 is an apocalyptic number.

645648786 is an abundant number, since it is smaller than the sum of its proper divisors (789126414).

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

645648786 is a wasteful number, since it uses less digits than its factorization.

645648786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11956470 (or 11956464 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 54.

The square root of 645648786 is about 25409.6199499323. The cubic root of 645648786 is about 864.3018572973.

The spelling of 645648786 in words is "six hundred forty-five million, six hundred forty-eight thousand, seven hundred eighty-six".