21124137 has 8 divisors (see below), whose sum is σ = 28820704. Its totient is φ = 13755168.

The previous prime is 21124123. The next prime is 21124141. The reversal of 21124137 is 73142112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21124137 - 2⁶ = 21124073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21128137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81748 + ... + 82005.

It is an arithmetic number, because the mean of its divisors is an integer number (3602588).

Almost surely, 2^21124137 is an apocalyptic number.

It is an amenable number.

21124137 is a deficient number, since it is larger than the sum of its proper divisors (7696567).

21124137 is a wasteful number, since it uses less digits than its factorization.

21124137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163799.

The product of its digits is 336, while the sum is 21.

The square root of 21124137 is about 4596.1001947303. The cubic root of 21124137 is about 276.4349762677.

Adding to 21124137 its reverse (73142112), we get a palindrome (94266249).

The spelling of 21124137 in words is "twenty-one million, one hundred twenty-four thousand, one hundred thirty-seven".