33213440 has 88 divisors (see below), whose sum is σ = 85974000. Its totient is φ = 12238848.

The previous prime is 33213437. The next prime is 33213469. The reversal of 33213440 is 4431233.

It is a super-2 number, since 2×33213440² = 2206265193267200, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66311 + ... + 66809.

Almost surely, 2^33213440 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 33213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42987000).

33213440 is an abundant number, since it is smaller than the sum of its proper divisors (52760560).

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

33213440 is a wasteful number, since it uses less digits than its factorization.

33213440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 519 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 33213440 is about 5763.1102713726. The cubic root of 33213440 is about 321.4434788618.

Adding to 33213440 its reverse (4431233), we get a palindrome (37644673).

The spelling of 33213440 in words is "thirty-three million, two hundred thirteen thousand, four hundred forty".