21027270 has 32 divisors (see below), whose sum is σ = 55054080. Its totient is φ = 5097440.

The previous prime is 21027257. The next prime is 21027271. The reversal of 21027270 is 7272012.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21027271) 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 15 ways as a sum of consecutive naturals, for example, 31530 + ... + 32189.

It is an arithmetic number, because the mean of its divisors is an integer number (1720440).

Almost surely, 2^21027270 is an apocalyptic number.

21027270 is an abundant number, since it is smaller than the sum of its proper divisors (34026810).

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

21027270 is a wasteful number, since it uses less digits than its factorization.

21027270 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63740.

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 21027270 is about 4585.5501305732. The cubic root of 21027270 is about 276.0117879863.

Adding to 21027270 its reverse (7272012), we get a palindrome (28299282).

The spelling of 21027270 in words is "twenty-one million, twenty-seven thousand, two hundred seventy".