691660541 has 8 divisors (see below), whose sum is σ = 812580384. Its totient is φ = 580414320.

The previous prime is 691660511. The next prime is 691660559. The reversal of 691660541 is 145066196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691660541 - 2¹⁰ = 691659517 is a prime.

It is a super-4 number, since 4×691660541⁴ (a number of 36 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 691660495 and 691660504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691660511) 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 7 ways as a sum of consecutive naturals, for example, 2418251 + ... + 2418536.

It is an arithmetic number, because the mean of its divisors is an integer number (101572548).

Almost surely, 2^691660541 is an apocalyptic number.

It is an amenable number.

691660541 is a deficient number, since it is larger than the sum of its proper divisors (120919843).

691660541 is a wasteful number, since it uses less digits than its factorization.

691660541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4836811.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 691660541 is about 26299.4399370025. The cubic root of 691660541 is about 884.3638873206.

The spelling of 691660541 in words is "six hundred ninety-one million, six hundred sixty thousand, five hundred forty-one".