21372033 has 8 divisors (see below), whose sum is σ = 28530208. Its totient is φ = 14230944.

The previous prime is 21372031. The next prime is 21372041. The reversal of 21372033 is 33027312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21372033 - 2¹ = 21372031 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21372031) 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, 991 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (3566276).

Almost surely, 2^21372033 is an apocalyptic number.

It is an amenable number.

21372033 is a deficient number, since it is larger than the sum of its proper divisors (7158175).

21372033 is an equidigital number, since it uses as much as digits as its factorization.

21372033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8543.

The product of its (nonzero) digits is 756, while the sum is 21.

The square root of 21372033 is about 4622.9896171201. The cubic root of 21372033 is about 277.5121137476.

Adding to 21372033 its reverse (33027312), we get a palindrome (54399345).

The spelling of 21372033 in words is "twenty-one million, three hundred seventy-two thousand, thirty-three".