33938721 has 6 divisors (see below), whose sum is σ = 49022610. Its totient is φ = 22625808.

The previous prime is 33938713. The next prime is 33938761. The reversal of 33938721 is 12783933.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 28740321 + 5198400 = 5361^2 + 2280^2 .

It is not a de Polignac number, because 33938721 - 2³ = 33938713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (33938701) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 1885476 + ... + 1885493.

It is an arithmetic number, because the mean of its divisors is an integer number (8170435).

Almost surely, 2^33938721 is an apocalyptic number.

It is an amenable number.

33938721 is a deficient number, since it is larger than the sum of its proper divisors (15083889).

33938721 is a wasteful number, since it uses less digits than its factorization.

33938721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3770975 (or 3770972 counting only the distinct ones).

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

The square root of 33938721 is about 5825.6948941736. The cubic root of 33938721 is about 323.7664354640.

It can be divided in two parts, 339 and 38721, that added together give a triangular number (39060 = T₂₇₉).

The spelling of 33938721 in words is "thirty-three million, nine hundred thirty-eight thousand, seven hundred twenty-one".