645863970 has 16 divisors (see below), whose sum is σ = 1550073600. Its totient is φ = 172230384.

The previous prime is 645863969. The next prime is 645864001. The reversal of 645863970 is 79368546.

645863970 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 10764370 + ... + 10764429.

It is an arithmetic number, because the mean of its divisors is an integer number (96879600).

Almost surely, 2^645863970 is an apocalyptic number.

645863970 is an abundant number, since it is smaller than the sum of its proper divisors (904209630).

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

645863970 is a wasteful number, since it uses less digits than its factorization.

645863970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21528809.

The product of its (nonzero) digits is 1088640, while the sum is 48.

The square root of 645863970 is about 25413.8538990056. The cubic root of 645863970 is about 864.3978657759.

The spelling of 645863970 in words is "six hundred forty-five million, eight hundred sixty-three thousand, nine hundred seventy".