691388334 has 144 divisors (see below), whose sum is σ = 1987575408. Its totient is φ = 171569664.

The previous prime is 691388293. The next prime is 691388413. The reversal of 691388334 is 433883196.

It is a super-3 number, since 3×691388334³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 691388334.

It is a congruent number.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 193149 + ... + 196695.

It is an arithmetic number, because the mean of its divisors is an integer number (13802607).

Almost surely, 2^691388334 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691388334, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993787704).

691388334 is an abundant number, since it is smaller than the sum of its proper divisors (1296187074).

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

691388334 is a wasteful number, since it uses less digits than its factorization.

691388334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3599 (or 3589 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 691388334 is about 26294.2642794964. The cubic root of 691388334 is about 884.2478565928.

The spelling of 691388334 in words is "six hundred ninety-one million, three hundred eighty-eight thousand, three hundred thirty-four".