21033270 has 80 divisors (see below), whose sum is σ = 59067360. Its totient is φ = 5360256.

The previous prime is 21033263. The next prime is 21033277. The reversal of 21033270 is 7233012.

It is an interprime number because it is at equal distance from previous prime (21033263) and next prime (21033277).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033277) 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 39 ways as a sum of consecutive naturals, for example, 18066 + ... + 19194.

It is an arithmetic number, because the mean of its divisors is an integer number (738342).

Almost surely, 2^21033270 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21033270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29533680).

21033270 is an abundant number, since it is smaller than the sum of its proper divisors (38034090).

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

21033270 is a wasteful number, since it uses less digits than its factorization.

21033270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171 (or 1162 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 21033270 is about 4586.2043129368. The cubic root of 21033270 is about 276.0380382356.

Adding to 21033270 its reverse (7233012), we get a palindrome (28266282).

The spelling of 21033270 in words is "twenty-one million, thirty-three thousand, two hundred seventy".