691868160 has 120 divisors (see below), whose sum is σ = 2396213820. Its totient is φ = 184492032.

The previous prime is 691868123. The next prime is 691868171. The reversal of 691868160 is 61868196.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 644753664 + 47114496 = 25392^2 + 6864^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8026 + ... + 38054.

Almost surely, 2^691868160 is an apocalyptic number.

691868160 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691868160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1198106910).

691868160 is an abundant number, since it is smaller than the sum of its proper divisors (1704345660).

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

691868160 is a wasteful number, since it uses less digits than its factorization.

691868160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30058 (or 30039 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 691868160 is about 26303.3868541677. The cubic root of 691868160 is about 884.4523663582.

It can be divided in two parts, 6918 and 68160, that added together give a triangular number (75078 = T₃₈₇).

The spelling of 691868160 in words is "six hundred ninety-one million, eight hundred sixty-eight thousand, one hundred sixty".