691379128045 has 8 divisors (see below), whose sum is σ = 832161466080. Its totient is φ = 551432294160.

The previous prime is 691379127997. The next prime is 691379128049. The reversal of 691379128045 is 540821973196.

It is a happy number.

691379128045 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 691379128045 - 2³³ = 682789193453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691379128049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208874215 + ... + 208877524.

It is an arithmetic number, because the mean of its divisors is an integer number (104020183260).

It is a 1-persistent number, because it is pandigital, but 2⋅691379128045 = 1382758256090 is not.

Almost surely, 2^691379128045 is an apocalyptic number.

It is an amenable number.

691379128045 is a deficient number, since it is larger than the sum of its proper divisors (140782338035).

691379128045 is a wasteful number, since it uses less digits than its factorization.

691379128045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417752075.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 691379128045 in words is "six hundred ninety-one billion, three hundred seventy-nine million, one hundred twenty-eight thousand, forty-five".