21494105 has 4 divisors (see below), whose sum is σ = 25792932. Its totient is φ = 17195280.

The previous prime is 21494101. The next prime is 21494107. The reversal of 21494105 is 50149412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15555136 + 5938969 = 3944^2 + 2437^2 .

It is not a de Polignac number, because 21494105 - 2² = 21494101 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21494101) 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, 2149406 + ... + 2149415.

It is an arithmetic number, because the mean of its divisors is an integer number (6448233).

Almost surely, 2^21494105 is an apocalyptic number.

It is an amenable number.

21494105 is a deficient number, since it is larger than the sum of its proper divisors (4298827).

21494105 is an equidigital number, since it uses as much as digits as its factorization.

21494105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4298826.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 21494105 is about 4636.1735299706. The cubic root of 21494105 is about 278.0394721655.

The spelling of 21494105 in words is "twenty-one million, four hundred ninety-four thousand, one hundred five".