691228080 has 360 divisors, whose sum is σ = 2554742736. Its totient is φ = 173560320.

The previous prime is 691228073. The next prime is 691228081. The reversal of 691228080 is 80822196.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (691228081) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 18681822 + ... + 18681858.

Almost surely, 2^691228080 is an apocalyptic number.

691228080 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 691228080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1277371368).

691228080 is an abundant number, since it is smaller than the sum of its proper divisors (1863514656).

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

691228080 is a wasteful number, since it uses less digits than its factorization.

691228080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 691228080 is about 26291.2167843179. The cubic root of 691228080 is about 884.1795326139.

The spelling of 691228080 in words is "six hundred ninety-one million, two hundred twenty-eight thousand, eighty".