21242937 has 8 divisors (see below), whose sum is σ = 28665504. Its totient is φ = 13991168.

The previous prime is 21242917. The next prime is 21242939. The reversal of 21242937 is 73924212.

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

It is a cyclic number.

It is not a de Polignac number, because 21242937 - 2⁶ = 21242873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21242939) 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, 42408 + ... + 42905.

It is an arithmetic number, because the mean of its divisors is an integer number (3583188).

Almost surely, 2^21242937 is an apocalyptic number.

It is an amenable number.

21242937 is a deficient number, since it is larger than the sum of its proper divisors (7422567).

21242937 is an equidigital number, since it uses as much as digits as its factorization.

21242937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85399.

The product of its digits is 6048, while the sum is 30.

The square root of 21242937 is about 4609.0060750665. The cubic root of 21242937 is about 276.9522219028.

The spelling of 21242937 in words is "twenty-one million, two hundred forty-two thousand, nine hundred thirty-seven".