21972803 has 2 divisors, whose sum is σ = 21972804. Its totient is φ = 21972802.

The previous prime is 21972763. The next prime is 21972809. The reversal of 21972803 is 30827912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21972803 - 2¹² = 21968707 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21972803.

It is not a weakly prime, because it can be changed into another prime (21972809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10986401 + 10986402.

It is an arithmetic number, because the mean of its divisors is an integer number (10986402).

Almost surely, 2^21972803 is an apocalyptic number.

21972803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21972803 is an equidigital number, since it uses as much as digits as its factorization.

21972803 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 21972803 is about 4687.5156533072. The cubic root of 21972803 is about 280.0884202044.

The spelling of 21972803 in words is "twenty-one million, nine hundred seventy-two thousand, eight hundred three".