21545434 has 32 divisors (see below), whose sum is σ = 36080640. Its totient is φ = 9609600.

The previous prime is 21545429. The next prime is 21545441. The reversal of 21545434 is 43454512.

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 15 ways as a sum of consecutive naturals, for example, 41094 + ... + 41614.

It is an arithmetic number, because the mean of its divisors is an integer number (1127520).

Almost surely, 2^21545434 is an apocalyptic number.

21545434 is a deficient number, since it is larger than the sum of its proper divisors (14535206).

21545434 is a wasteful number, since it uses less digits than its factorization.

21545434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606.

The product of its digits is 9600, while the sum is 28.

The square root of 21545434 is about 4641.7059363988. The cubic root of 21545434 is about 278.2606202861.

Adding to 21545434 its reverse (43454512), we get a palindrome (64999946).

The spelling of 21545434 in words is "twenty-one million, five hundred forty-five thousand, four hundred thirty-four".