645902786 has 8 divisors (see below), whose sum is σ = 972278544. Its totient is φ = 321809940.

The previous prime is 645902771. The next prime is 645902797. The reversal of 645902786 is 687209546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 645902786.

It is an unprimeable number.

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, 570020 + ... + 571151.

It is an arithmetic number, because the mean of its divisors is an integer number (121534818).

Almost surely, 2^645902786 is an apocalyptic number.

645902786 is a deficient number, since it is larger than the sum of its proper divisors (326375758).

645902786 is a wasteful number, since it uses less digits than its factorization.

645902786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1141456.

The product of its (nonzero) digits is 725760, while the sum is 47.

The square root of 645902786 is about 25414.6175654878. The cubic root of 645902786 is about 864.4151820102.

It can be divided in two parts, 64590 and 2786, that added together give a palindrome (67376).

The spelling of 645902786 in words is "six hundred forty-five million, nine hundred two thousand, seven hundred eighty-six".