21272803 has 2 divisors, whose sum is σ = 21272804. Its totient is φ = 21272802.

The previous prime is 21272759. The next prime is 21272819. The reversal of 21272803 is 30827212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21272803 - 2⁹ = 21272291 is a prime.

It is equal to p_1346092 and since 21272803 and 1346092 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21272843) 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 as a sum of consecutive naturals, namely, 10636401 + 10636402.

It is an arithmetic number, because the mean of its divisors is an integer number (10636402).

Almost surely, 2^21272803 is an apocalyptic number.

21272803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272803 is an equidigital number, since it uses as much as digits as its factorization.

21272803 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21272803 is about 4612.2448980946. The cubic root of 21272803 is about 277.0819525788.

The spelling of 21272803 in words is "twenty-one million, two hundred seventy-two thousand, eight hundred three".