21540146 has 8 divisors (see below), whose sum is σ = 32463984. Its totient is φ = 10718820.

The previous prime is 21540083. The next prime is 21540157. The reversal of 21540146 is 64104512.

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

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 3 ways as a sum of consecutive naturals, for example, 25100 + ... + 25943.

It is an arithmetic number, because the mean of its divisors is an integer number (4057998).

Almost surely, 2^21540146 is an apocalyptic number.

21540146 is a deficient number, since it is larger than the sum of its proper divisors (10923838).

21540146 is a wasteful number, since it uses less digits than its factorization.

21540146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51256.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21540146 is about 4641.1362832824. The cubic root of 21540146 is about 278.2378534738.

Adding to 21540146 its reverse (64104512), we get a palindrome (85644658).

The spelling of 21540146 in words is "twenty-one million, five hundred forty thousand, one hundred forty-six".