33378921 has 12 divisors (see below), whose sum is σ = 49517572. Its totient is φ = 21650976.

The previous prime is 33378889. The next prime is 33378937. The reversal of 33378921 is 12987333.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16040025 + 17338896 = 4005^2 + 4164^2 .

It is not a de Polignac number, because 33378921 - 2⁵ = 33378889 is a prime.

It is a super-2 number, since 2×33378921² = 2228304734248482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33378941) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49786 + ... + 50451.

Almost surely, 2^33378921 is an apocalyptic number.

It is an amenable number.

33378921 is a deficient number, since it is larger than the sum of its proper divisors (16138651).

33378921 is a wasteful number, since it uses less digits than its factorization.

33378921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100280 (or 100277 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 33378921 is about 5777.4493507083. The cubic root of 33378921 is about 321.9764427296.

The spelling of 33378921 in words is "thirty-three million, three hundred seventy-eight thousand, nine hundred twenty-one".