33750021 has 4 divisors (see below), whose sum is σ = 45000032. Its totient is φ = 22500012.

The previous prime is 33750007. The next prime is 33750037. The reversal of 33750021 is 12005733.

It is a happy number.

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 not a de Polignac number, because 33750021 - 2⁷ = 33749893 is a prime.

It is a super-2 number, since 2×33750021² = 2278127835000882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 33750021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33750071) 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, 5625001 + ... + 5625006.

It is an arithmetic number, because the mean of its divisors is an integer number (11250008).

Almost surely, 2^33750021 is an apocalyptic number.

It is an amenable number.

33750021 is a deficient number, since it is larger than the sum of its proper divisors (11250011).

33750021 is a wasteful number, since it uses less digits than its factorization.

33750021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11250010.

The product of its (nonzero) digits is 630, while the sum is 21.

The square root of 33750021 is about 5809.4768267031. The cubic root of 33750021 is about 323.1652705316.

Adding to 33750021 its reverse (12005733), we get a palindrome (45755754).

The spelling of 33750021 in words is "thirty-three million, seven hundred fifty thousand, twenty-one".