691090449 has 16 divisors (see below), whose sum is σ = 1053747072. Its totient is φ = 394662528.

The previous prime is 691090447. The next prime is 691090451. The reversal of 691090449 is 944090196.

It is an interprime number because it is at equal distance from previous prime (691090447) and next prime (691090451).

It is not a de Polignac number, because 691090449 - 2¹ = 691090447 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 691090449.

It is not an unprimeable number, because it can be changed into a prime (691090441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27427 + ... + 46199.

It is an arithmetic number, because the mean of its divisors is an integer number (65859192).

Almost surely, 2^691090449 is an apocalyptic number.

It is an amenable number.

691090449 is a deficient number, since it is larger than the sum of its proper divisors (362656623).

691090449 is a wasteful number, since it uses less digits than its factorization.

691090449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20536.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 691090449 is about 26288.5992209551. The cubic root of 691090449 is about 884.1208454771.

The spelling of 691090449 in words is "six hundred ninety-one million, ninety thousand, four hundred forty-nine".