21054937 has 4 divisors (see below), whose sum is σ = 21066256. Its totient is φ = 21043620.

The previous prime is 21054923. The next prime is 21054941. The reversal of 21054937 is 73945012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21054937 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21054899 and 21054908.

It is not an unprimeable number, because it can be changed into a prime (21054967) 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 3 ways as a sum of consecutive naturals, for example, 2139 + ... + 6832.

It is an arithmetic number, because the mean of its divisors is an integer number (5266564).

Almost surely, 2^21054937 is an apocalyptic number.

It is an amenable number.

21054937 is a deficient number, since it is larger than the sum of its proper divisors (11319).

21054937 is an equidigital number, since it uses as much as digits as its factorization.

21054937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11318.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21054937 is about 4588.5658979686. The cubic root of 21054937 is about 276.1327907181.

Adding to 21054937 its reverse (73945012), we get a palindrome (94999949).

The spelling of 21054937 in words is "twenty-one million, fifty-four thousand, nine hundred thirty-seven".