291628 has 6 divisors (see below), whose sum is σ = 510356. Its totient is φ = 145812.

The previous prime is 291619. The next prime is 291647. The reversal of 291628 is 826192.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 291596 and 291605.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36450 + ... + 36457.

2²⁹¹⁶²⁸ is an apocalyptic number.

It is an amenable number.

291628 is a deficient number, since it is larger than the sum of its proper divisors (218728).

291628 is a wasteful number, since it uses less digits than its factorization.

291628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72911 (or 72909 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 291628 is about 540.0259253036. The cubic root of 291628 is about 66.3146893949.

Subtracting from 291628 its sum of digits (28), we obtain a square (291600 = 540²).

It can be divided in two parts, 291 and 628, that added together give a palindrome (919).

The spelling of 291628 in words is "two hundred ninety-one thousand, six hundred twenty-eight".