21311073 has 16 divisors (see below), whose sum is σ = 36082560. Its totient is φ = 12177648.

The previous prime is 21311071. The next prime is 21311077. The reversal of 21311073 is 37011312.

It is not a de Polignac number, because 21311073 - 2¹ = 21311071 is a prime.

It is a super-2 number, since 2×21311073² = 908323664822658, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21311071) 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, 56190 + ... + 56567.

It is an arithmetic number, because the mean of its divisors is an integer number (2255160).

Almost surely, 2^21311073 is an apocalyptic number.

It is an amenable number.

21311073 is a deficient number, since it is larger than the sum of its proper divisors (14771487).

21311073 is a wasteful number, since it uses less digits than its factorization.

21311073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112773 (or 112767 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 21311073 is about 4616.3917728027. The cubic root of 21311073 is about 277.2480108366.

Adding to 21311073 its reverse (37011312), we get a palindrome (58322385).

The spelling of 21311073 in words is "twenty-one million, three hundred eleven thousand, seventy-three".