33721161 has 4 divisors (see below), whose sum is σ = 44961552. Its totient is φ = 22480772.

The previous prime is 33721139. The next prime is 33721189. The reversal of 33721161 is 16112733.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 33721161 - 2¹¹ = 33719113 is a prime.

It is a super-2 number, since 2×33721161² = 2274233398375842, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (33721361) 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, 5620191 + ... + 5620196.

It is an arithmetic number, because the mean of its divisors is an integer number (11240388).

Almost surely, 2^33721161 is an apocalyptic number.

It is an amenable number.

33721161 is a deficient number, since it is larger than the sum of its proper divisors (11240391).

33721161 is a wasteful number, since it uses less digits than its factorization.

33721161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11240390.

The product of its digits is 756, while the sum is 24.

The square root of 33721161 is about 5806.9924229329. The cubic root of 33721161 is about 323.0731302494.

Adding to 33721161 its reverse (16112733), we get a palindrome (49833894).

The spelling of 33721161 in words is "thirty-three million, seven hundred twenty-one thousand, one hundred sixty-one".