21242037 has 8 divisors (see below), whose sum is σ = 29236480. Its totient is φ = 13704480.

The previous prime is 21241991. The next prime is 21242047. The reversal of 21242037 is 73024212.

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

It is not a de Polignac number, because 21242037 - 2⁶ = 21241973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242047) 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, 114112 + ... + 114297.

It is an arithmetic number, because the mean of its divisors is an integer number (3654560).

Almost surely, 2^21242037 is an apocalyptic number.

It is an amenable number.

21242037 is a deficient number, since it is larger than the sum of its proper divisors (7994443).

21242037 is a wasteful number, since it uses less digits than its factorization.

21242037 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228443.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21242037 is about 4608.9084390992. The cubic root of 21242037 is about 276.9483106339.

Adding to 21242037 its reverse (73024212), we get a palindrome (94266249).

The spelling of 21242037 in words is "twenty-one million, two hundred forty-two thousand, thirty-seven".