33628391 has 4 divisors (see below), whose sum is σ = 33650232. Its totient is φ = 33606552.

The previous prime is 33628381. The next prime is 33628393. The reversal of 33628391 is 19382633.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19382633 = 197 ⋅98389.

It is a cyclic number.

It is not a de Polignac number, because 33628391 - 2⁶ = 33628327 is a prime.

It is a super-2 number, since 2×33628391² = 2261737362497762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33628393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8420 + ... + 11753.

It is an arithmetic number, because the mean of its divisors is an integer number (8412558).

Almost surely, 2^33628391 is an apocalyptic number.

33628391 is a deficient number, since it is larger than the sum of its proper divisors (21841).

33628391 is a wasteful number, since it uses less digits than its factorization.

33628391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21840.

The product of its digits is 23328, while the sum is 35.

The square root of 33628391 is about 5798.9991377823. Note that the first 3 decimals coincide. The cubic root of 33628391 is about 322.7765902306.

The spelling of 33628391 in words is "thirty-three million, six hundred twenty-eight thousand, three hundred ninety-one".