691491101 has 4 divisors (see below), whose sum is σ = 790275552. Its totient is φ = 592706652.

The previous prime is 691491091. The next prime is 691491161. The reversal of 691491101 is 101194196.

691491101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 691491101 - 2⁶ = 691491037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691491161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49392215 + ... + 49392228.

It is an arithmetic number, because the mean of its divisors is an integer number (197568888).

Almost surely, 2^691491101 is an apocalyptic number.

It is an amenable number.

691491101 is a deficient number, since it is larger than the sum of its proper divisors (98784451).

691491101 is an equidigital number, since it uses as much as digits as its factorization.

691491101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98784450.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 691491101 is about 26296.2183783144. The cubic root of 691491101 is about 884.2916655460.

The spelling of 691491101 in words is "six hundred ninety-one million, four hundred ninety-one thousand, one hundred one".