21305454 has 16 divisors (see below), whose sum is σ = 45117648. Its totient is φ = 6684032.

The previous prime is 21305423. The next prime is 21305461. The reversal of 21305454 is 45450312.

It is a super-2 number, since 2×21305454² = 907844740292232, which contains 22 as substring.

21305454 is a modest number, since divided by 5454 gives 2130 as remainder.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 104337 + ... + 104540.

It is an arithmetic number, because the mean of its divisors is an integer number (2819853).

Almost surely, 2^21305454 is an apocalyptic number.

21305454 is an abundant number, since it is smaller than the sum of its proper divisors (23812194).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21305454 is a wasteful number, since it uses less digits than its factorization.

21305454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208899.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21305454 is about 4615.7831404866. The cubic root of 21305454 is about 277.2236417600.

Adding to 21305454 its reverse (45450312), we get a palindrome (66755766).

The spelling of 21305454 in words is "twenty-one million, three hundred five thousand, four hundred fifty-four".