33721040 has 40 divisors (see below), whose sum is σ = 79042560. Its totient is φ = 13378176.

The previous prime is 33721027. The next prime is 33721049. The reversal of 33721040 is 4012733.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×33721040² = 2274217077363200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33721049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8501 + ... + 11819.

It is an arithmetic number, because the mean of its divisors is an integer number (1976064).

Almost surely, 2^33721040 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 33721040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39521280).

33721040 is an abundant number, since it is smaller than the sum of its proper divisors (45321520).

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

33721040 is a wasteful number, since it uses less digits than its factorization.

33721040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3459 (or 3453 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 33721040 is about 5806.9820044495. The cubic root of 33721040 is about 323.0727438264.

Adding to 33721040 its reverse (4012733), we get a palindrome (37733773).

The spelling of 33721040 in words is "thirty-three million, seven hundred twenty-one thousand, forty".