21905054 has 8 divisors (see below), whose sum is σ = 32905440. Its totient is φ = 10936576.

The previous prime is 21905053. The next prime is 21905071. The reversal of 21905054 is 45050912.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21905053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6179 + ... + 9054.

It is an arithmetic number, because the mean of its divisors is an integer number (4113180).

Almost surely, 2^21905054 is an apocalyptic number.

21905054 is a deficient number, since it is larger than the sum of its proper divisors (11000386).

21905054 is a wasteful number, since it uses less digits than its factorization.

21905054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15954.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 21905054 is about 4680.2835384194. The cubic root of 21905054 is about 279.8002572038.

Adding to 21905054 its reverse (45050912), we get a palindrome (66955966).

The spelling of 21905054 in words is "twenty-one million, nine hundred five thousand, fifty-four".