645557106 has 16 divisors (see below), whose sum is σ = 1293099264. Its totient is φ = 214854864.

The previous prime is 645557089. The next prime is 645557117. The reversal of 645557106 is 601755546.

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 7 ways as a sum of consecutive naturals, for example, 78466 + ... + 86301.

It is an arithmetic number, because the mean of its divisors is an integer number (80818704).

Almost surely, 2^645557106 is an apocalyptic number.

645557106 is an abundant number, since it is smaller than the sum of its proper divisors (647542158).

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

645557106 is a wasteful number, since it uses less digits than its factorization.

645557106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165425.

The product of its (nonzero) digits is 126000, while the sum is 39.

The square root of 645557106 is about 25407.8158447357. The cubic root of 645557106 is about 864.2609460223.

The spelling of 645557106 in words is "six hundred forty-five million, five hundred fifty-seven thousand, one hundred six".