691396563 has 32 divisors (see below), whose sum is σ = 1087414272. Its totient is φ = 385228800.

The previous prime is 691396561. The next prime is 691396577. The reversal of 691396563 is 365693196.

It is not a de Polignac number, because 691396563 - 2¹ = 691396561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691396561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107118 + ... + 113388.

It is an arithmetic number, because the mean of its divisors is an integer number (33981696).

Almost surely, 2^691396563 is an apocalyptic number.

691396563 is a deficient number, since it is larger than the sum of its proper divisors (396017709).

691396563 is a wasteful number, since it uses less digits than its factorization.

691396563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6555.

The product of its digits is 787320, while the sum is 48.

The square root of 691396563 is about 26294.4207580239. The cubic root of 691396563 is about 884.2513647258.

The spelling of 691396563 in words is "six hundred ninety-one million, three hundred ninety-six thousand, five hundred sixty-three".