691217128092 has 12 divisors (see below), whose sum is σ = 1612839965576. Its totient is φ = 230405709360.

The previous prime is 691217128079. The next prime is 691217128097. The reversal of 691217128092 is 290821712196.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×691217128092² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691217128097) 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 3 ways as a sum of consecutive naturals, for example, 28800713659 + ... + 28800713682.

Almost surely, 2^691217128092 is an apocalyptic number.

It is an amenable number.

691217128092 is an abundant number, since it is smaller than the sum of its proper divisors (921622837484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691217128092 is a wasteful number, since it uses less digits than its factorization.

691217128092 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57601427348 (or 57601427346 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 48.

The spelling of 691217128092 in words is "six hundred ninety-one billion, two hundred seventeen million, one hundred twenty-eight thousand, ninety-two".