33720091 has 4 divisors (see below), whose sum is σ = 33731784. Its totient is φ = 33708400.

The previous prime is 33720083. The next prime is 33720107. The reversal of 33720091 is 19002733.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 19002733 = 109 ⋅174337.

It is a cyclic number.

It is not a de Polignac number, because 33720091 - 2³ = 33720083 is a prime.

It is a super-2 number, since 2×33720091² = 2274089074096562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33720391) 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, 1911 + ... + 8431.

It is an arithmetic number, because the mean of its divisors is an integer number (8432946).

Almost surely, 2^33720091 is an apocalyptic number.

33720091 is a deficient number, since it is larger than the sum of its proper divisors (11693).

33720091 is an equidigital number, since it uses as much as digits as its factorization.

33720091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11692.

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 33720091 is about 5806.9002918941. The cubic root of 33720091 is about 323.0697130884.

The spelling of 33720091 in words is "thirty-three million, seven hundred twenty thousand, ninety-one".