691863552601 has 4 divisors (see below), whose sum is σ = 745083825892. Its totient is φ = 638643279312.

The previous prime is 691863552581. The next prime is 691863552637. The reversal of 691863552601 is 106255368196.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 97922055625 + 593941496976 = 312925^2 + 770676^2 .

It is a cyclic number.

It is not a de Polignac number, because 691863552601 - 2⁹ = 691863552089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691863552001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26610136626 + ... + 26610136651.

It is an arithmetic number, because the mean of its divisors is an integer number (186270956473).

Almost surely, 2^691863552601 is an apocalyptic number.

It is an amenable number.

691863552601 is a deficient number, since it is larger than the sum of its proper divisors (53220273291).

691863552601 is a wasteful number, since it uses less digits than its factorization.

691863552601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53220273290.

The product of its (nonzero) digits is 2332800, while the sum is 52.

The spelling of 691863552601 in words is "six hundred ninety-one billion, eight hundred sixty-three million, five hundred fifty-two thousand, six hundred one".