691228404 has 60 divisors (see below), whose sum is σ = 1815751168. Its totient is φ = 229294800.

The previous prime is 691228403. The next prime is 691228409. The reversal of 691228404 is 404822196.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691228403) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 63309 + ... + 73419.

Almost surely, 2^691228404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691228404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907875584).

691228404 is an abundant number, since it is smaller than the sum of its proper divisors (1124522764).

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

691228404 is a wasteful number, since it uses less digits than its factorization.

691228404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10338 (or 10327 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 691228404 is about 26291.2229460708. Note that the first 3 decimals coincide. The cubic root of 691228404 is about 884.1796707613.

The spelling of 691228404 in words is "six hundred ninety-one million, two hundred twenty-eight thousand, four hundred four".