21797073 has 8 divisors (see below), whose sum is σ = 32292000. Its totient is φ = 14531364.

The previous prime is 21797063. The next prime is 21797093. The reversal of 21797073 is 37079712.

It is not a de Polignac number, because 21797073 - 2¹³ = 21788881 is a prime.

It is a super-2 number, since 2×21797073² = 950224782734658, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21797003) 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 7 ways as a sum of consecutive naturals, for example, 403623 + ... + 403676.

It is an arithmetic number, because the mean of its divisors is an integer number (4036500).

Almost surely, 2^21797073 is an apocalyptic number.

It is an amenable number.

21797073 is a deficient number, since it is larger than the sum of its proper divisors (10494927).

21797073 is an equidigital number, since it uses as much as digits as its factorization.

21797073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807308 (or 807302 counting only the distinct ones).

The product of its (nonzero) digits is 18522, while the sum is 36.

The square root of 21797073 is about 4668.7335541879. The cubic root of 21797073 is about 279.3397410572.

The spelling of 21797073 in words is "twenty-one million, seven hundred ninety-seven thousand, seventy-three".