645671802 has 16 divisors (see below), whose sum is σ = 1291606272. Its totient is φ = 215180160.

The previous prime is 645671783. The next prime is 645671827. The reversal of 645671802 is 208176546.

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, 37527 + ... + 51957.

It is an arithmetic number, because the mean of its divisors is an integer number (80725392).

Almost surely, 2^645671802 is an apocalyptic number.

645671802 is an abundant number, since it is smaller than the sum of its proper divisors (645934470).

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

645671802 is a wasteful number, since it uses less digits than its factorization.

645671802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21893.

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 645671802 is about 25410.0728452321. The cubic root of 645671802 is about 864.3121273469.

The spelling of 645671802 in words is "six hundred forty-five million, six hundred seventy-one thousand, eight hundred two".