645970911 has 32 divisors (see below), whose sum is σ = 940896000. Its totient is φ = 392652288.

The previous prime is 645970909. The next prime is 645970921. The reversal of 645970911 is 119079546.

It is not a de Polignac number, because 645970911 - 2¹ = 645970909 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645970921) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 979900 + ... + 980558.

It is an arithmetic number, because the mean of its divisors is an integer number (29403000).

Almost surely, 2^645970911 is an apocalyptic number.

645970911 is a deficient number, since it is larger than the sum of its proper divisors (294925089).

645970911 is a wasteful number, since it uses less digits than its factorization.

645970911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303.

The product of its (nonzero) digits is 68040, while the sum is 42.

The square root of 645970911 is about 25415.9578021368. The cubic root of 645970911 is about 864.4455716267.

The spelling of 645970911 in words is "six hundred forty-five million, nine hundred seventy thousand, nine hundred eleven".