21311037 has 24 divisors (see below), whose sum is σ = 33808320. Its totient is φ = 12828480.

The previous prime is 21311033. The next prime is 21311051. The reversal of 21311037 is 73011312.

It is not a de Polignac number, because 21311037 - 2² = 21311033 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311033) 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 in 23 ways as a sum of consecutive naturals, for example, 15889 + ... + 17177.

It is an arithmetic number, because the mean of its divisors is an integer number (1408680).

Almost surely, 2^21311037 is an apocalyptic number.

It is an amenable number.

21311037 is a deficient number, since it is larger than the sum of its proper divisors (12497283).

21311037 is a wasteful number, since it uses less digits than its factorization.

21311037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473 (or 1470 counting only the distinct ones).

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

The square root of 21311037 is about 4616.3878736519. The cubic root of 21311037 is about 277.2478547217.

Adding to 21311037 its reverse (73011312), we get a palindrome (94322349).

The spelling of 21311037 in words is "twenty-one million, three hundred eleven thousand, thirty-seven".