691080 has 64 divisors (see below), whose sum is σ = 2237760. Its totient is φ = 169728.

The previous prime is 691079. The next prime is 691109. The reversal of 691080 is 80196.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 691080.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 691080.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1339 + ... + 1781.

It is an arithmetic number, because the mean of its divisors is an integer number (34965).

2⁶⁹¹⁰⁸⁰ is an apocalyptic number.

691080 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 691080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1118880).

691080 is an abundant number, since it is smaller than the sum of its proper divisors (1546680).

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

691080 is a wasteful number, since it uses less digits than its factorization.

691080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 691080 is about 831.3122157168. The cubic root of 691080 is about 88.4116389608.

Multiplying 691080 by its sum of digits (24), we get a triangular number (16585920 = T₅₇₅₉).

The spelling of 691080 in words is "six hundred ninety-one thousand, eighty".