645106890 has 64 divisors (see below), whose sum is σ = 1574899200. Its totient is φ = 169089024.

The previous prime is 645106879. The next prime is 645106901. The reversal of 645106890 is 98601546.

645106890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645106879) and next prime (645106901).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 693946 + ... + 694874.

It is an arithmetic number, because the mean of its divisors is an integer number (24607800).

Almost surely, 2^645106890 is an apocalyptic number.

645106890 is an abundant number, since it is smaller than the sum of its proper divisors (929792310).

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

645106890 is a wasteful number, since it uses less digits than its factorization.

645106890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311.

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 645106890 is about 25398.9545060422. The cubic root of 645106890 is about 864.0599854400.

The spelling of 645106890 in words is "six hundred forty-five million, one hundred six thousand, eight hundred ninety".